alright, well i checked out this beat up iroc-z to see if i could savage any parts the guy took the 350 out of it. but he wants to sell the rear end with posi traction for 300 dollars and only 90,000 miles on them. my car has 2.73s. if anyone could tell me what kindof gearing is in the back that would be great. its an 88 iroc-z with the 350 and i believe it came standard with an automatic

 

SinceI am not sure which axle it is here is all of them (posi)
1988-1989 V-8
axle code/gear ratio
6HT 2.73 posi
6hb/6hf 3.08 posi
6HQ/6HJ 3.23 posi

Borg Warner
GH3 2.77 posi
GW6 3.27 posi
GM3 3.45 posi

Hope this helped a little.

 

Most common if a 350 autowas 2:77 9-Bolt with a option for that year a 3:27 9-bolt. If it is a 2:77 and the price is $300 tell him a $150 max for that ratio or the 3:27 $200 Max and that should include the rear disc brakes.