Conference napalm::musclecars

    Well I guess I'll start.. I've got a question.. Do you think a
    Chev. 10bolt posi will take the abuse of a 400 - 500 hp big block??
    
    Changing the stock posi unit to a hipo one w/quick change gears,
    and changing the axles will be some of the mod's to this thing..
    
    WILL IT LAST W/THE HP??
    
    Mike......

    Mike,
    
    A stock 10 bolt posi will work for awhile.  It depends on the driver.  If
    you like to rev it up, and side step the clutch it isn't going to last very
    long, and if you are planning to use slicks, a 10 bolt probably wouldn't 
    last one run.
    
    I run a 400-500 hp big-block in a Corvette, and haven't had any
    problems with the stock 10 bolt posi.  I am reasonably carefull to
    avoid side stepping the clutch, and this particular 10 bolt hasn't seen
    any dragstrip runs.
    
    The previous 10 bolt was removed only due to it's ratio being wrong for
    what I want to do with the car...  it was 4:10 to 1, great for the
    dragstrip, but not too good for the hiway.  I checked it to see if any
    damage had been done, and couldn't find any.  Even the ring gear bolts
    were still tight.  This particular 10 bolt had seen about 20 passes in
    the 1/4 mile, and about 20k miles of use on the street since it had
    been rebuilt.  
    
    I can't recommend using a 10 bolt for what you want to do...  or even
    a 12 bolt for that matter.  The best way to get something that will
    last is to go with a Ford 9 inch, or a DANA 60.  In the long run it
    will probably be cheaper than trying to build up a 10 bolt to take 
    the power. 
    
    Tom
    

    Tom,
      Well to start the car is an auto and it's going to stay an auto..
    So I won't have to worry about the side stepin... Also the car will 
    only (probably) see like 10 runs a year if that in the 1/4..  It's
    going to be a show car that get's drivin a little.. As for the driver
    well I do like to mash the floor with my foot but...can't beat the
    hell out of something you've got 15K invested in...
    
    So what kind of fabrication is involved in fitting a 9" in and 
    which years or models work the best....any ideas???
    Mike...

Bolting in a 9" really isn't all that difficult.  You will have to get one the 
correct width for your Camaro.  then it's just a matter of having the bracketry
removed from your stock rear end and put on the 9".  If you can't find one the 
correct width you can get a wider one (at least 4" wider than needed so the
axels can be resplined) and get it narrowed.  Then it is a matter of bolting it
in, connecting up brake lines, and an emergancy brake cable.  You will also
have to use wheels with a Ford bolt pattern or have the ford axels and drums
redrilled to the Chevy pattern.

Here in CXO, a used posi 9" will run you about $150, welding the brackets on
will cost about $75, and if the rearend/axels need to be narrowed it should 
run about $300+-.  You can buy one complete, rebuilt, and ready to go from
outfits such as Currie Enterprises but, it will set you back a cool $1500.

Since it sounds like you will be putting some real horsepower to it, you may
want to consider getting a 31 spline (vs. a 28 spline).  For the posi they
come in 2 varieties, a clutch type (traction lok) and a gear type (Detriot
locker).  The Detriot can be a little unruley on the streeb but works fine.  
If it is a drag only car, then you can get a spool which locks the rear.

I've been researching this for possible use in my Vega.

Hope this helps out.

Mark

    Ok, Let's say I got a 9" out of a lincoln Vers. with disc brakes.
    Will this one work? And with the disc set up what kind of other mods 
    will I have to make to get the brakes to work? (master cyl,lines,
    E -brake cables)..
     
     Could i buy axels (strange) with chev. bolt pat. and ford inners to 
    make them work with the 9". or do you think a dana or a 12bolt would
    be a better investment???
    
     Thanks in advance,
    Mike............

      Mike,
    
    Since you are not planning to race it a bunch, and it is going to 
    stay an automatic, a 12 bolt should be enough.  I don't know if it will
    be a better investment, but it will probably be a lot easier to fit to 
    your car than the 9" Ford.  Heck, with  a little TLC, you could probably 
    live with a well prepared 10 bolt.  Just don't use the water trap, and 
    *DON'T* run slicks.  As far as aftermarket axles go, it depends on how
    much $$$ you have to spend.  

    If you decide to go with the disks on the rear, you will have to change
    the master cylinder to one that will work with disks on all four 
    wheels.  And you will probably need to use some kind of proportioning
    valve to get the proper balance between front and rear brakes.  It's
    not an impossible job, it just adds to the complexity of the rear
    end conversion.
    
    Tom
    
    P.S.  The post-mortem on a shelled out rear gear set is kinda
    interesting.  I've always been amazed that a large chunk of metal 
    will fit between the ring and pinion gears.  It doesn't do the gears
    any good, but a cube 1/4"x1/4"x1/4" will fit... no problem.  :-)  Kinda
    made some interesting skid marks too.

    You may want to check NHRA rules for a car capable of the ET's you're
    shooting for. They may not allow a 12 bolt rear, unless it's somehow
    modified to retain the axle shafts in the event one should break. The
    only thing that holds the axles on are those c-clips in the rear end.
    Blow a chuck or snap an axle and the wheel is going its own way.
    
    Harry
    

    Pontiac offered disk brake rears on the T/A in the late '70s.  I'd
    think one of those master cylinders would do the trick for you.
    Matt

    Well a freind of mine just got his r.end back from Cal. He's putting
    it in a 76' Camaro that he made Pro-Street. 427ci. Auto. I thought it
    was a 12bolt but it's only a 10 so I think I'll be able to keep the
    10bolt and put in a quick change posi unit,to change gears quicker.
    (for the track and to go to shows and on weekends.)
    
    I think it'll work...
    
    Tom can you elaborate on your p.s. in your last note...?
    Mike..........

Mike,

If you do go with a 10 bolt (or, a 12 bolt), both Moroso and Auburn Gear make
HD posi units that are supposed to be much more durable than stock.  They will
set you back about $260 mail order.

Mark

    
    Mike,
    
    re: my .6  
    
    My brother Larry once bought a car with a blown-up rear end.  We fished
    out all of the pieces, (we thought) and installed a used gear set.
    
    Worked fine for about a week, then a piece of the old gear set got
    run between the ring and pinion.  Naturally, Larry was in the
    process of accelerating at WOT...  Larry said it made an awful bang,
    then a series of clunks, then locked up completely.  He backed it up
    to unlock it, and drove it about 2 miles home, with it locking up about
    every block or so. 
    
    This time we didn't have to worry about fishing any pieces out of the
    housing, as the housing was destroyed.  We found several pieces that
    had obviously gone through the ring and pinion set...  There were
    several teeth missing on the ring gear, and lots of marks on the pinion
    gear.
    
    Tom
    
    
     

In my quest for either a 28 spline posi pumpkin, or a Chrysler 8-3/4" posi I
have found a 4.56 geared 9" pumpkin with a mini spool.  The gearing is a little
low but that can be changed.

Can a locked rear end be run on the street?  I know that the wheels will be
turning at different speeds around corners.  The car will probably only see
a few hundred street miles per year.  Has anyone ever used a spool on the 
street?  

Thanks,
Mark

    Mark
    
    That should be real fun on wet or snowy corners! 
    
    Another trait that is nasty w/a locked rear is front tire
    adhesion in a turn varies with "weight in the trunk" and
    "loud pedal depression".
    
    My detroit locker was that way. Coast around the corner was
    ok, but if I goosed it and didn't break'em loose the ditches 
    got too close for me!
    
    Being locked always, coasting is out. Front tire life will
    be shorter too.
    
    IMHO
    Randy

    Don't do it! A spool is an off-road item only. Randy is right about the
    problem with steering and it will break axles like toothpicks. 
    
    Please use some kind of center section designed for the street and save
    the spool for the track. 
    
    IMHO
    
    Don B

    Here's another 'no' vote. Steering is a very iffy proposition with a
    spool. Forget it totally if the road is wet! You're going straight!
    
    Harry
    

Well, thanks guys.  You confirmed what i figured was true.

I think that the rear end problem may be solved.  It looks like I am going to 
pick up a non-posi Chryser 8-3/4".  I can't find a posi anything.  I can get a
good, complete 8-3/4 for $100.  I can get a brand new posi unit (for list price)
from the local dealer for $190.  That's half of the price for the Ford unit.
The local chassis shop will narrow the housing, narrow/respline the axels, and
weld on the needed brackets for $300.

Does anyone know of a discount mail order place for Chrysler Motorsports
parts?

Thanks,
Mark

    Mark, Summit has some Mopar Performance stuff listed in their catalogs.
    Don't know how competitive their prices are though.
    
    Harry
    

    Whoooa! $300 is a lot to narrow that rear end. Greg Moser Eng. in
    Portland Ind. does 'em complete for $150 (housing and axles). They're
    at least worth a quick phone call. They advertise in Hot Rod and Car
    Craft.
    
    Watch what you get done to those axles. Shortening and re-splining is
    the way to go if you can't afford custom axles like Strange's but STAY
    AWAY from any kind of welded axle.
    
    Stan

    Has anyone tried this or know if it will work. My 71 Monte Carlo
    currently has an 8.5" 2:73 geared open carrier, C-clip style. I have an
    8.2" 3:36 geared posi carrier, c-clip style from a '69 GTO on my bench. 
    Can the 8.2" posi carrier be swapped into the axle housing (along with 
    the appropriate ring and pinion)?
    From everything I've read it appears that GM only changed the carrier
    when it introduced the 8.5" in 71 not the axle housing itself.
    

    Whats the formular for figuring gear ratio with out taking the cover
    off and counting teeth?
    
    I have approx 3 1/3 turns of the pinion for 1 turn of the axle.. Any
    ideas out there??

    3 1/3 turns is approximately 3.36. 
    
    Chris

    I have a question for the 4-wheel drive experts. My neighbor is parting
    out his '79 Ford Bronco, and I am taking the rear diff. (9", 3.55
    Sure-trak) for the Torino. I know it will need to be shortened
    slightly, but that is not the question. What I was wondering is if the
    front center chuck is the same as the rear? For instance, can you
    simply bolt it into a rear housing and use it, or are the gears
    reversed? This is just to satisfy my curiosity, not to try it.
                                                     John M.
    

    John, if the front driveshaft goes in at the top of the diff (as it
    should on a stock '79 Ford) then the axle is mounted upside down (to
    get a better angle on the u-joints) and the ring and pinion are indeed
    reverse rotation so the wheels will turn the right way.
    
    The front axle is a Dana 44 anyway, so the parts wouldn't fit into your
    9 inch rear. :-(
    
    Harry
    

    Thanks Harry. The question was for the owner, I already begged him for
    the rear diff, and he was wondering if he should pull the fromt chuck to
    have as a spare for his 73 MACH-1. 
                                                            John M.
    

    A friend of mine recently aquired a 1967 Camaro. The car is a true
    RS/SS350.  The previous owner replaced the rear end with a 10 bolt.
    My friend was given the 12 bolt that was removed. We are trying
    to determine if this is the original rear from the car. It shows signs
    of where the traction bar mounting bracket was torched off,(it is
    welded on the 10 bolt), and also has the single leaf spring pads.
    The numbers stamped into the axle tube are : QLO1 11G    We cannot find
    these numbers listed in our books. Does anyone have a reference manual
    to de-code this number? I would like to know what year,etc. this
    actually is if not `67.
    
    Thanks,
    
    John

    
     I'm trying to figure some final drive ratios, and I'm a bit unsure of
    how exactly to do this. Do I add the rear end ratio to whatever gear
    ratio the transmissionis in to arrive at a final, or is it more
    complicated than that? ie; 4:90 rear + 2:54 trans = 7:44 final
    
    

4.90 *times* 2.54 = 12.45.

Bruce

    
    Does anyone have any experience having a rear end housing straightened?
    It seems that the forces involved with slicks, a big block and a
    transbrake have caused the housing ends to move forward. I plan to
    install a housing brace (custom) after the straightning process.
    
    thanks
    
    db
    

Call Chic Brignolo in Dedham.  I believe he's listed under Speed Equipment 
in the yellow pages.  He has jigs and fixtures for aligning differential 
housings and axle tubes.

I had a guy in Billerica do mine.  I wouldn't recommend him to anyone after 
having to replace BOTH axle bearings in less that 2500 miles at the state 
fairgrounds in Oklahoma City.

Brignolo Chassis can do it right.

If you can't locate his number, call Bellmont's Rod & Custom in Dedham at 
617-326-9599.  Billy Belmont knows Chicky's number.

    
    I suppose that I should have said that this is a "Left Coast" kind of a
    problem....I'm in Seattle.
    
     I have found a welder that will align the housing and weld on a brace
    for $300. I have seen this guy's work and he is close to an artist. All
    I need now is a PO from the "Minister of Finance" and we should be
    rockin'.
    
    thanks
    
    Don Berry
    

Don,

Another option is to UPS the housing to Greg Moser Engineering and have them 
do the work.  They advertise in the back of all of the car rags. They are 
located in Indiana (or one of the other "I" states).  I shipped my housing 
and axels to them (from Colorado) to get the narrowing/resplining work done
when building the Vega.

Mark

One thing you want to remember and that is to have the housing aligned 
*AFTER* you do all of your welding on it or do the welding while measuring 
the housing's alignment.

The hot setup is a solid bar that clamps on the differential carrier cradle 
(where the carrier bearings normally fit) and extends out through the axle 
tube.  A machined sleeve is then fitted over the outboard end and that is
what the machinist uses as a base to measure concentricity.

    I wish I had the guts to charge $300 to do 20 min. of welding and
    5 min of hyd. press time......
    
    
    Tne Mad Weldor...Jim

re .52

That's the way that mine was done.  The guy that welded the brackets on for me
checked the housing for straightness before and after welding the bracketry on.

Mark

    Unless he's recently got into this, Greg Moser's won't straighten a
    rear end. The way they jig them ensures perfect alignment when they
    narrow them.
    
    I'd suggest calling Art Morrison's (advertises in most mags). He's in
    Washington too, Yakima or Tacoma I think, and while he's primarily a
    chassis shop he should be able to put you onto someone locally who can
    do this. I don't think this is such a big deal that it has to be
    shipped all over the country.
    
    Besides, packaging those things is a bugger!
    
    
    Stan

    
    Any recommendations for shops who can properly set up my Ford 9"
    Traction-lok with a new ring and pinion?  I called Bill Belmore at
    Comp gear, and he estimated a ballpark price (part/labor) of ~$500.
    That seems pricey, though I'm sure his work would be impeccable.
    
    Any other suggestions in the Merrimack Valley, 3M areas?
    
    Tom

    Tom, is the $500 quote for parts and labor? If so, that's a great
    price. If it's just for labor then it's WAY out of line! :-)
    
    Harry
    

    
    Tom,
    
    Do it yourself and save! I did the research and decided that there was
    no rocket sceince involved. Get a book, read it every day for a week,
    measure twice and spend the money on your wife. Then she'll let you buy
    anything that you want.
    
    Don
    
    P.S. I was quoted $175 labor ot set the ring and pinion on my 12 Bolt.
    
    

If you DIY, have a good set of micrometers to check the bushings and thrust 
plates.  There's more to setting up a differential than simply "getting the 
pattern right", especially when you're dealing with a posi or locker.

Check the tolerances on the spiders and the support pin.  Check the 
tolerances on the spiders and the axle splines.  Check the wear on the 
clutch dogs, etc.

    Re .40
    
    I'm gonna verify the balances carefully in my checking account.
    Then, with great precision, write out a check to Competition Gear.
    
    Maybe on the 10 bolt in my Malibu, but on a mega-dollar 9", 31 spline,
    N-cased Locker, I'm not risking the trial and error that often
    accompanies DIY projects......
    
    I've helped set up a 12 bolt GM, and the "basic" principles are simple.
    However, there's more than a bit of subtlety involved...
    
    Thanks for the tips!
    
    Tom
    
    

I have a friend who is the current IHRA E/Dragster national record holder who
does rear ends, 4 speeds and automatics on the side.  He just rebuilt my big
dollar 540 cubic inch rat motor and I highly recommend him. He has done
    tons of 9 inch fords.  

If interested you should call performance city, Thursday after 5 and ask for 
cliff.
           Performanc city is in downtown natick.  508-653-5159
    

Phil

    I'm still gathering parts for the "back burner Falcon". I have a Ford
    9" and a couple of Jag rears in stock. Since the car will be driven on
    the street and taken to the drags a few times, I'm wondering if the
    8-3/4 Jag will be strong enough for the 302. I'd like to have the car
    handle, but I also will be adding unwanted weight with the Jag rear. 
    (I want this project to alot lighter than any late model Mustang)
    If I use the 9" I know it will be strong enough, but I want to be able to
    handle some curves on the street. What do ya' think?
    
    TMW
    

    Actually Jim the 9" might be overkill for a hot small block.  I've
    seen some pretty stout small blocks that the 8" proved more than
    capable of handling.  However, these vehicles were all automatic trans
    equipped.  If you plan on running a stick you may indeed need that 9"
    after all.  It's just that the 8" is bunches lighter than the 9", and
    thus reduces unsprung weight and consequently improves handling.
    
    Then again, the Jag rear end does give one full bragging rights.  Also,
    I've seen many Jag style rear-ends under hot big block Cobra replicas.
    So.....who really knows????
    
    Tom 

    Tom,
    I have a brand new 5 speed to add on behind the blow shield....
    The Jag would be hidden and if I break it...I'll have to do some
    wrenching to remove it. Course I might design the rear frame to
    accomidate working on it if it became necessary. In fact, not much of 
    the original Falcon sheet metal will be there after I finish with 
    the plasma torch... I intend to have this puppy on a very strict diet.
    
    
    TMW  

    
    I disassembled my 9" Ford this weekend and found that a Cashew nut sized 
    chunk of pinion gear tooth had busted off.  There was nothing in the 
    performance of the diff to indicate a problem prior to my finding the
    broken tooth..
    
    Also a casual observation that well used Hypoid lube stinks like hell!!
    I spilled a bunch on the shop floor, and despite repeated cleaning
    efforts the whole shop reeks!!
    
    The chuck is now safely in Bill Belmore's shop awaiting a 3.50 ring and
    pinion and general freshening up.  Should yield a substantial
    performance improvement over the current 3.00 ring and pinion...
    
    Tom

    Tom,
    
     Don't forget to change the driven gear for the speedo in the trans to
    correct for the gear change. You should do it now before we have to
    start putting the driveline back in that beast.
    
    Chris

    Do posi trac rearends require a special gear oil?
    	68 Firebird is the application. One book says yes but doesn't state
    what it should be an another says nothing about it. Anyone know for
    sure?
    
    thanks, paul

    re: .48
    Yes, GM requires special gear lube for "limited slip differentials"
    (posi). A good idea is to add a bottle of "limited slip diff. lube
     additive" to the gear oil to prevent the clutches from chattering.
    This can be bought at a GM dealer over the counter.
    
    John

    
    Just picked up my 9" chuck from Bill Belmore.  He completely went
    through it and found a multitude of sins.  It appears that the
    differential has been serviced before, and a "few" key components
    were left out upon re-assembly.  
    
    Water over the dam I guess, now it's right - with new bearings,
    clutches, and a spanking new Strange axles 3.50 ring and pinion.
    
    Only $630.  OUCH!!!!!
    
    Let's hope this wakes up the car some...
    
    Tom

I just fininshed re-installing the (Bill Bellmore rebuilt) transmission in 
my '63 Vette, and for the next major project, I am considering changing out 
the rear end from the correct, stock one, to something a little more fun 
to drive around town. 

The original owner was one of 221 people (out of 21k+ Vettes manufactured 
that year) that ordered the 3.08 non-posi (for better mileage/top end).  
Unfortuantely that equates to terrible acceleration...   :\(

In reading up on Vette rear ends, it appears that '63 - '79s are 
interchangable, and there were 3 individual castings/cases used: 

	2.73 - 3.08		3.23 - 3.90		4.11 +

I'd like to keep the original unit intact for the future -and- at the same 
time move up to a posi unit, so it would seem I'll be looking for another 
complete center section. Everything I've read says the 1/2 shafts should fit 
from one to the other.

The car is a freshly rebuilt 327/300hp, 10.5:1, with the stock, wide ratio T10. 
With the 3.08s, 1st or 2nd gear is about it for around town driving, and it 
turns about 2,500 RPM for 60 mph. It is driven less than 1,000 miles a year, 
and only on dry days. Given that the car has 4 wheel (non-power assisted) drum 
brakes, panic slow downsfrom more than 55 mph are "interesting" (after years 
of performance cars that had power brakes), so going > 70 mph for any distance 
would be unlikely, in the 1,000 or less miles the car is driven each year. 

My preference would be to get something around 4.11 - 4.56. Doing some quick 
math, 4.56s would run the RPMs up about 50% higher than the 3.08s, putting 
60 mph at about 3,700 RPM. The biggest differences would be in reduced 
mileage (for all 1000 miles a year), reduced top end (that I wouldn't use 
anyway), the ability to use all 4 gears around town, and how fast it reached 
60 mph...  :\) 

Any thoughts/recommendations?

Jack

    
      Jack,
    
    Go for it!  Just remember, it is very easy to find the red line
    with a 4.56:1 ratio.  Also, my Camaro with a 4.56:1
    gear ratio tended to run somewhat warmer than it did with the 
    3.08:1 ratio.  If your cooling system is border line now, the 
    lower gear ratio will push it over the edge on hot summer days.
    
    Tom
    
    

    What is the redline of your engine?  A 4.56 gear will keep your motor
    around that area a lot, and the higher revs will contribute to the
    added heat as -1 said.  4.11 is probably as high as you'd want,
    especially if you red line at 6500 or so, but then again you only drive
    1000 miles so a 4.56 may not be all that bad.  Just remember when
    you get on the freeway to go to a cruise, you'll be the dude in the
    slow lane going 60 with your motor screaming.  :^)

    The benefit of this is when you step on the gas, you disappear (up
    until you top out a few seconds later).  I visibly demonstrated
    this phenomenon :^) to a 90 Mustang GT at 70mph.  I had just put the gear 
    in and it impressed me for sure.  I stepped up from a 3.42 so, you'll
    see even more of an improvement.  

    I was putt-putting along at 70 and was overtaking the GT doing about
    65, when I got next to him, he whacked it... and I did too.  I shot
    by him so bad, I seriously put about 100 feet on him in a few seconds
    and backed off.  He finally came by me with a paper sack over his head
    so he couldn't see that the $#!+eatin grin on my face was so big you
    couldn't punch it off.  YEE-HA, I love this stuff!

    Ya, a 4.11'll probably be the ticket.  Also CHECK YOUR PULLEYS.  If
    you're going to make a habit of twisting it, make sure everything is
    up to the task, including the pulleys.  

If memory serves, the 300 HP version of the small block likes to be shifted at
maybe 5500 or so, or possibly a tad more, but definitely under 6000. Redline is
probably no more than 6000, as well - maybe less.

The thing is, with the wide-ratio gearbox and 3.70s, you've got the equivalent
of *better* than a 4.11 rear if you had the more traditional close-ratio box
that came with those gears from the factory. Doing the arithmetic, and assuming
a 2.52 first gear in your 4-speed, you've got the equivalent of a 4.24 geared
close-ratio (2.20 first) combination. This holds up very well all through the
first three gears, and then you have that major drop from third to fourth that
is common to all the wide ratio boxes, that the close-ratio model avoids. In
other words, the wide-ratio box has essentially the same gear steps, same drop
in rpm, etc. through the first three ratios that the close-ratio box has.

Out on the highway with a 3.70, you'd be at 3000 rpm or a bit more. Since the
torque peak of that engine is probably around 3200 or so, you'd have *lovely*
throttle response, without straying too too far into that "gimme another gear"
scenario that a 4.11 or greater gear would undoubtedly create.

From 0 - 30, more gear gets you more acceleration, assuming no traction woes.
Once you pass 25-30 mph, there will be essentially no difference between your
current 3.08s, and, say, 3.70s, or even 4.56s. Not that the car won't be more
responsive in any given gear (such as fourth, out on the highway). It's just
that the speed range of any given gear is reduced with more aggressive gearing,
so that, say, at a 60 mph crack, your current 3.08 combination will be at 4700
rpm approaching the HP peak in second gear (HOT DAMN!), while a 4.56 geared
combo will undoubtedly be forced to start in fourth gear at around 3700 rpm or
so. In that case the 3.08s would have an advantage, since getting to the power
peak is *the best you can do* at any given road speed. This is not to say that
3.08s will always have an advantage at speed. It's just that who's in what gear
at what speed (and engine speed) will be the decider, and it's a tossup.

If it were me, 3.70s would be close to perfect for that car.

Bruce

This may not be an issue on a Corvette, but make sure all your speedometer
gears will work before you do such a large-percentage swap of gears.


steve

This is great - there were a lot of ideas - some that I had thought about -
like topping out at redline on the highway really early, (especially given 
the redline on this rebuild is supposed to be 6,000), and maybe thinking 
about a more moderate ratio like 4.11, and what the heck will the speedo 
read if I can't get the right speedo gear?

The ones that I hadn't thought about were: temperature - it already runs hot 
(180 - 215) on warm summer days with 10.5:1 (gained from being .060 over), and 
the belts and pulleys ability to withstand long periods of higher than normal 
RPMs.

At an informal cruise night at PC Creams in Hudson, (Ma) last night, a new 
re-aquaintance from 18 years in my past suggested another alternative - 
according to him, Zoom just started making a 3.70 set that WILL fit in the 
3.08 carrier. He also mentioned that he currently has 4.11's in his '62 fuelie, 
and that he is looking to drop back to about 3.70 as well.

Jim also mentioned that the non-stock aluminum fan might not stand the 
constant higher RPMs of a 4+ RE ratio.

The 2.54 first gear (vs the 2.20) with the 3.70 should make for much 
improved acceleration, but still offer a reasonable RPM while cruising at 
highway speeds too. 

It looks like we're going to price out the 3.70 Zoom gear conversion, and 
see if we can afford it now, or whether I'll have to wait for Christmas...  ;\)

Thanks!

Jack

    Does anyone know of a place in the New England area that can remove
    the axle tubes from a GM 12 bolt and put them back in the proper
    orientation?  The right axle tube in my father's '69 El Camino has 
    rotated in the 3rd member. The left one appears to have done the same 
    thing, though to a lesser degree. This causes major driveline geometry
    problems. The previous owner drag raced it for years and apparently
    felt that the factory welds (in 2 places on each tube) was sufficient.
    He should have welded them the entire circumference. 
    
    Chris

    re:.57
    
    Chris,
    
    Give Danny Burmer a call in Millbury,Mass. He has the jigs and stuff
    set up for that. His number is (508)865-9250. He runs one of those 
    wheel standers. I think its an old VW pick up....
    Or you can try Lindblad Chassis in Northbridge,Mass. (508)234-8283
    
    John

    John,
    
     Thanks, I'll give them a call.
    
    Chris

    Can anyone give me a rough idea of cost for a 12 bolt posi w/373 gears
    that will fit a 67' Camaro?
                                     Thanks,
                                              Sean

    } Can anyone give me a rough idea of cost
    A lot.  If you can find it in the junk yard.
    Even more ($1200-1500) to buy one made for you.
    Or you can build your own unit
    (get the case, axles, gear, posi)  Take the rest of the stuff off any
    rear end.
    
    Figure aftermarket posi = $300, axles $300, gear $150.  There goes
    $750... plus labor.
    
    MadMike

    Thanks Mike. A 10 bolt posi would be fine. I'm not that particular,
    
    I'm just looking for prices/suggestions.
    
    Sean