I have a 8.5 10 bolt out of an 83 1/2 ton pickup, it has 3.73 posi which is very desirable to me. I also have a 79 model Camaro 8.5 10 bolt with 2.73 limited slip. My car is a 92 with 383 and 4L60, question is how much would I have to narrow one of these and which would be better. I have a professional welder at work who can mount all of the brackets to match my current rearend, he also said that the torque arm provision would be fairly simple. Question number two is how tough is the 8.5 compared to a 12 bolt or ford 9 inch (which would never be found in my car)?

 

the 2nd gen uses leaf springs, the 3rd is a 4 link coil, by the time you swap over the carrier and gears, narrow the axle, weld on perches and have a pretty much frankensteined axle you could get a decked out 12 bolt from moser for about the same price and its got all the best stuff, you would have a half assed rigged unit trying to mess with the 2nd gen axle.

[This message has been edited by TempesT68 (edited December 02, 2001).]

 

3rd is a 3 link not 4.

Buy an aftermarket 12 bolt or 9" if you feel the 7.5" isn't enough. You'll be better off than trying to fabricate a non third gen diff into the car.

You could use the 8.5" if you really want to. It would have to be narrowed meaning having to purchase aftermarket shorter axles. I wouldn't bother trying to mount the torque arm to a cast iron housing. Go with ladder bars or a 4-linked back half chassis instead.

There's nothing wrong with your 92's diff that a little improvements can't fix. You already have 28 spline axles. They're not as strong as aftermarket 28 spline but they're still stronger then the older 26 spline axles. Weld the axle tubes and install a rear cover with bearing supports.

My car still uses a beefed up 7.5" diff although I'll be switching to a 9" this winter to take the abuse of a transbrake.

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The 8.5 is quite a bit stronger than 7.5, almost as strong as the 12 bolt. The '79 Camaro should be about the same width as the Nova rear I have in my '57, close to the same as our 3rd gen; if anything it might be narrower.

If you look at the way Strange & Currie put the torque arm mount on a 12-bolt or 9 inch, it really is simple.

Get your tape measure out and check the flange-to-flange width of your stock rear and the two you have (not just the backing plate width). If it is close enough, put the 3.73 gears & carrier into the '79 rear, get the brackets changed by your welder friend, and go for it. It's bound to cost you less than beefing up a 7.5 or buying a 12 bolt or 9 inch (assuming your friend isn't on the clock, that is).

If you have to change the width of that 8.5, forget it. Beef up your 7.5 or shell out for a 12-bolt.

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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4, 2300 stall TC. Ported World 305 heads, Crane PowerMax 2050 cam. ZZ3/4 intake, oil pump, pan & baffle. Accel HEI SuperCoil & module. Hooker 2055 headers, 3" Catco cat & 3" catback w/dual-opposite Flowmaster 80. 2.93 limited slip. Spohn SFCs waiting to be installed. AMSOIL syn lubes bumper-to-bumper. Daily year-round driver. Best ET, speed TBD...
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Well, to change everything from the 7.5 to the 8.5 will cost about 350 dollars, which is about a fourth of what an empty Mosier 12 bolt costs. I also prefer the clutchless positrac that is in my 8.5 over the limited slip. Many people have told me that the positrac in that rearend wasn't very good quality, but my brother put a built 454 with 100hp nitrous shot in front of it and had no problems, even with slicks. Thank you for the advice and input on this subject.

 

The 8.5" 10 bolt is a good rear.....AND you can put a Torsen T2R differential in it. You can't really do that with a 12 bolt/Ford 9"/Dana 60.

 

how do you only cost 350 to get an axle from something else under one of these cars ?



interesting


oh and the stock LS to stay away from is the gov-lok

very common in the 9.5" 10 oblts and the truck 12 bolts

their nickname is the grenade-lok