[Gooatee]

What is the fastest you can go with a stock rear? What mods can be done to prolong life and safety?
Is it worth doing these mods or is a 12 bolt or 9 inch the answer?

I have a 74 GTO with the stock rear (10 bolt posi w/4.10's) and I am probably going to be looking at mid 11's when the new combo is complete. I am looking for options (on a budget) to keep from blowing up the rear!(lol) Thanks for all responses!

[Gooatee]

What is the fastest you can go with a stock rear? What mods can be done to prolong life and safety?
Is it worth doing these mods or is a 12 bolt or 9 inch the answer?

I have a 74 GTO with the stock rear (10 bolt posi w/4.10's) and I am probably going to be looking at mid 11's when the new combo is complete. I am looking for options (on a budget) to keep from blowing up the rear!(lol) Thanks for all responses!

[shark landis]

I have seen full bodied Novas in the nines on an 8.5. Your 8.2 is slightly weaker, but your probably not packing the front wheels or pulling 1.40 60' times, either. You should be ok to go 11s, but if you plan on building horspower and/or running slicks, go to a 12-bolt. The Ford rear eats about 30 hp or so due to the angles involved. Camaro or Nova units are still around and there now are aftermarket pieces available. Good luck. Ron

['ol Pinion head]

Have built-up a few 10 bolts in '72 or '73-74 X-body 8.5 housings that went in cars that continually ran low 10's in 1/4 with spool, aftermarket axles, & T/A Performance or LPW rear support cover. Have to weld center section to axle tubes, reinforce leaf spring perchs, c-clip elims, or better...custom bolt in axles.

Don't forget to not use the '74 GTO's stock Spicer 1310 u-joint flange. Can use a '75 & later stock GM spicer 1330 flange or go aftermarket 1350 from Randy's Ring & Pinion or other sources.

[Skip Fix]

My 78 TA is running 7.00s in the 1/8 on stock axles and an Eaton posi. I am purposely keeping the 9" slicks though to let them hopefully break loose before something breaks! Going to a 12 bolt with this motor in another car for safety.
I know the Parker's 78 TA in Dallas ran stock rears in the 10s on spray til they broke then got another.

OPH can give his opinion, Tom's Differentials says usually the stock posi breaks before the axles.

[Gooatee]

Thanks fellas! Shark, mine is a 8.5 not 8.2! I have stock posi, 4.10 gears and stock axles at the moment! Just wondering do I spend the money on this rear or add a couple hundered and go 9 inch? Looking at going 9 inch but if I can safely add a few things to this rear and survive into low 11's I might just go that route! OPH, I like your thinking, the only drawback is the spool. I would still like to street this thing a little and they can be a DRAG on the street!

[DAVE RIBEIRO]

Gooatee,

I would weld the tubes,first, then use a spool, w/C-clip elim.kit and good axles....Add
bars and go racing...Do it right the first time
and save money in the long run..good-luck Dave,1033/stock Come to MIR on the 4/12 and check it out....

[Ron]

Don't go to the 9 inch. You will be down in power if your do, approximately 2-3%. 8.5 is good with after market axels, spool or posi, etc. After that go to the 12 bolt, unless you are going to make lots and lots of power.

Ron

[b-man]

Runnin' the 9 in mine.

Nice to have the 'poor man's quick-change' if you want to swap ratios. Mine has all stock Ford stuff in it, including a Detroit Locker and 31-spline axles. I plan to upgrade to a spool and aftermarket axles when the need arises (going faster).

The housing has a backbrace welded to it, keeps things in check when you are racing with slicks. My car has a very mild 455 in it and runs in the low 12s right now, but I like the fact that it is strong enough to take plenty more when I decide to upgrade my engine.

10 years on the transbrake and never a whine out of it, I would say get the 9 if you can. Hasn't slowed me down one bit.

Let's go racing!
www.outlawpontiacs.com/members/B-Man2.php
www.outlawpontiacs.com/members/B-Man.php

[Cliff R]

Follow the advice above and WELD the tubes in place. I raced mine for part of last year before welding the tubes and the factory welds were cracked! The stock carriers are so-so, I lunched one shortly after installing the new 455. Still using stock axles with C clip elims, holding up OK for now. I only run 9" DOT's and they slip a bit on the launch which is probably saving a lot of parts breakage......Cliff

[Brian Baker]

Keith, you saw how much "abuse" my rear took without a failure. It was stock! Of course, if you recall, I did have the posi rebuilt in it with new clutches and spiders, but I attributed that more to it having 20+ years of wear on it.

Have the tubes squared to the housing and welded. Go buy a T/A cover/girdle, and some Moser axles with C-clip eliminators and it should hold up quite well in your car even deep into the 10's when you're ready.