stock 10bolt 3.08 geared rear question

[band77one]

ok so im deciding on either 3.42 gears or 3.73 havent quite decided yet, but i have a question, im reading my summit catalog and it says thi

GM 10-bolt, 7.5"
1.438" diameter, 27 spline pinion

GM 10-Bolt, 8.5"
1.626 diameter 30spline pinion

how do i know which is mine ? i have a 1988 Iroc-Z Camaro, with the 305 TPI engine, stock Lim. Slip 3.08 geared rear.

Can someone perhaps tell me which one to order from ? thanks.

[WildBillyT]

No 8.5" ten bolt was installed under a 3rd gen.

71-81 Camaros only.

Jeg's does a better job online with that kind of stuff:

http://www.jegs.com/webapp/wcs/stores/servlet/CategoryDisplay?lang=-1&catalogId=10002&storeId=10001&categoryId=13563

Although they say that the 8.5" was under a 70 Camaro and that is incorrect... but everything else looks right.

but order wherever you want.

[BonzoHansen]

Well, if it is a 3rd gen, it is generally either a 7.5 or one of them 9 bolt rears. What are they 7.65 or something? I forget.

[r0nin89]

Is there any difference in the 8.5" from the 7.5" width? I'm considering beefing an 8.5" 10bolt and was wondering if there will be any width problems like a 4th gen rear on a third gen.

[WildBillyT]

Well, if it is a 3rd gen, it is generally either a 7.5 or one of them 9 bolt rears. What are they 7.65 or something? I forget.

7.625, or 7 5/8.

Is there any difference in the 8.5" from the 7.5" width? I'm considering beefing an 8.5" 10bolt and was wondering if there will be any width problems like a 4th gen rear on a third gen.

Out of what? I don't know if any of them have the proper torque arm mount. The 71-81 ones are 61" wide, and are for leaf springs.

[band77one]

ok thanks all its a 7.5 10bolt