I have a 1987 iroc-z with a 350 TPI. I was wondering if the Iroc has posi. Also what gears did my car come stock with?? Thank you

 

Hold your brakes and press down the gas(called a burnout) if it leaves two sets of marks it's posi. Should be posi anyway if it's an iroc. If it has the 9-bolt it cmae with either 3.45 0r 3.23. If 10-bolt should have 3.08,2.77, or 3.42. Probably wrong on the gear options ,but I think I'm close. Check the main page.

 

Look up the RPO code in your glove compartment(sometimes helpful) or remove the rear cover( good time to change the fluid ang clean it out).

 

well my 86 z-28 had a 305 in it and it had a posi with 2.73 in it

 

You probably have a 9 bolt with a 3.27 posi.... but possibly only a 2.77.

If it's a 9 bolt, there will be a tag on the back cover that will say the ratio.

How to identify 9 bolts versus 10 bolts. Count the bolts holding on the back cover...