Too many choices

[Koll]

Looking at Summit mag now. There is about 5 Choices for a rear. 10 and 12 bolt. On the stock Camaro, is it the 10 or 12 (im guessing 10) Also, is it 7.5/7.625" dia. ring gear/1.438" dia 27 spline, 8.20" dia ring gear/1.438 dia pinion sptem 27 spline, 8.20" dia ring gear/1.438 dia 25 spline or 8.50 dia ring gear/1.625" dia (new style)?

Through brilliant deduction I believe that I have the 10bolt 7.5/7.625" dia. ring gear/1.438" dia 27 spline since it is the only one that offeres the 2.73 stock. Right or wrong?

[Batman]

On the IROC it is either an 9 or 10 bolt. 10 bolt is a 7.5oo" ring gear, i think the 9 is the 7.625" ring gear, not sure. Easiest way to tell is crawl under the car and count the bolts on the rear cover.

[Koll]

Damn. Why dont I think of these things WHILE im under the car (like yesterday)

[j0n]

u do not have a 9-bolt...no posi 2.73 = 10-bolt

[Koll]

Originally Posted by j0n

u do not have a 9-bolt...no posi 2.73 = 10-bolt

Oh yeah. Make fun of the kid without posi. Why dont you just goto the special olympics and make fun of them.

[Tru2Chevy]

if you have no posi and 2.73's you defintely have the 7.5/7.625" 10 bolt rear. In 88 you will probably have 28 spline axles (as opposed to earlier 3rd gens which have 26 spline). I think the switch was mid-year '87...if I'm wrong someone jump in with the right info.....

- Justin

[bad64chevelle]

I have no posi in my Camaro...but its because i destroyed the rear. If this damn snow keeps falling ill never be able to go get my 9" and get this thing haulin!

[ar0ck]

Originally Posted by Tru2Chevy

if you have no posi and 2.73's you defintely have the 7.5/7.625" 10 bolt rear. In 88 you will probably have 28 spline axles (as opposed to earlier 3rd gens which have 26 spline). I think the switch was mid-year '87...if I'm wrong someone jump in with the right info.....

- Justin

Your right Justin. Â*My old 1985 Trans Am was a 26-Spline non-posi 10-bolt 7.5.

For your car if your not planning on pushing over 400hp on drag radials I wouldnt bother with a 12-bolt. Â*Thats for serious cars running serious numbers on serious tires. Â*If your just going to make a simple ~350hp motor I would suggest using a 4th gen rear out of a Z28. Â*Perferably a manual car. Â*For its posi and 3.42 gear ratio. Â*It will easily handle the abuse of aan automatic low 3 digit horsepower rating without a problem, and you get the benefit of the more modern set-up (28-spline, Posi-traction, good gearing). Â*Their plenty of people here even with 4th gens still reliably running into the 11's on their stock rear end. Â*Also people here have picked up a good 4th gen rear end for around $200 bucks, when a 12-bolt costs around 2-3k fully loaded.