stevesz-28

will a 88 iroc posi trac or a later 3rd gen rear end fit on a 85 z28

ede

as long as it's from the same rear, say from a 10 bolt going to a 10 bolt. you could put a 9 bolt posi in a 10 bolt rear. you'd also want to make sure the axle splines matched, or get axles to match the carrier.

84 Z-28 350

do you mean the whole rear end assy, or just the internals, externally other than the brakes (disk vs. drum) they are identical, and will bolt up W/ no prob, as for the internals, there are 2 different rears, a 9 bolt, and a 10 bolt, the internals are completely different, and then on the 10 bolt they changed the axle spline from 26 to 28 somewhere between '88 and '89, and the spline count need to match the spline count of the carrier you are using.

stevesz-28

so your saing a camaro posi trac rear end will bolt up to a 85 z28? and what year camaros had posi trac? and how will i convrt it to the disc brakes?

84 Z-28 350

posi was available on all years of our cars as a option, the only way you can tell if it has a functioning unit is to raise the rear end, put the car in park/gear, whichever applicable and try to turn one of the weels (W/ a breaker bar...on a lug-nut), if it turns easy the posi is either worn out or it dosen't have one, if it takes allot of force, (I think the book says 50 ft- lbs but I'm not quite sure) the posi worksas for the disk conversion, it's easy, and there are a bunch of threads on it in the brake bords....I just don't remember it off the top of my head

Wadebryant

The first thing you should do is to educate yourself on the various OE codes used to identify the rear end, be it a 9 or 10 bolt. The id code is stamped on the passenger side axle tube and can be used to help determine the year, carrier and gear ratio. Haynes manuals have a brief code summary.

Here's another thread;Thirdgen Rearend Data

If your car is currently equipped with rear drums and you are considering going with a disk braked rear end, you must also change the brake proportioning valve to get the rear brakes to function properly. Goes without saying but, figure on new parking brake cables too and possibly the ebrake cable coupler. You may have to mix and match model year parts to get it all to work. Also, depending on the gears, if you change from say 2.73's to 3.27's etc., expect your speedo to be off a bit.

Pat Hall

iTrader: (31)

As far as ten bolt axle spline counts go, all 88's had 26 spline axles and most 89's did too. The changeover occurred about halfway through the 89 production year. My 89's original rear still had 26 spline axles in it. Any ten bolt from 90-92 is guaranteed to have 28 splines.