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/store...tegoryId=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]

Originally Posted by 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.

7.625, or 7 5/8.

Originally Posted by 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.

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