I wanted to test you all on your rear end knowledge, so here goes. I have a 1988 Camaro with a 2.73 ratio rear end. I know they upgraded the rear ends in 1987 and again in 90, I think, so I'd like to find a 87 and up rear end with the 3.42 posi unit. Question is, do you know if the 6-cyl rear ends are smaller, or are they they same? I noticed that many of the 6-cyl cars had this rear end, so it should be easy to find. Also, does anyone know if the 4th gen rear ends will fit under a third gen car without a big hassle? I ask because I've seen a few being parted out in the last few days. Thanks for any helpful info!

 

Everyone seems to think that! But no, the V6 rear axles are just as strong as the v8 axles of the same year. In fact, even the I-4 axles (82-85) were as strong as the v8 axles. The only place youll find a 3.73/open/drum axle is under a four cylinder f-body, 82-85, with a manual transmission.

And yeah, '89 was the crossover year between 26 and 28 spline. You're guaranteed to have 28 spline in '90, and guaranteed to have 26 spline in '88. But for '89, you've gotta pull the cover to check the axleshafts... the tendency is more for 26 spline in '89, but you never know 'till you look!

No 6 cylinder f-body got a posi from the factory, but the 85-89's with automatics did get a 3.42/open/drum rear. 4th gen rears fit, but are a bit wider, and you need different wheels to make up for this difference. If you do a <a href="search.php?s="><img src="images/top_search.gif" alt="Search" border="0"></a> in this forum, or (probalby more appropriate) in the Suspension/Chassis/Brakes forum, you'll find more info on the 4th gen rears.

What was upgraded on the rear axles in '87? Only other upgrade I was aware of was going from 7 1/2" ring to 7 5/8" ring in 1985 ... we're talking about 10 bolt axles, right?

 

Hey, thanks for the tips. I thought I had read that they changed something in 87, but it was 85 I was thinking of, when they went from hte 7.5 inch ring gear to the 7.65 inch. I've got a Camaro performance book, but so far it's proved to be vague on most subjects and worthless to me. From what you've told me, I'll probly try to find a 90-92 rear end. Thanks!

 

87 was when 9bolts became availible

 

Actually, 9 bolts were first available in 85.

Miles
Diff Solutions
www.9bolt.com

 

on the camaro? really, I didn't think they became an option till 87...oh well learn something new each day