Too many choices
 

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?

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.

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

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.

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

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!

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.