I have an 1988 IROC with the following RPO's :
GM3-3.45 9 Bolt rear axle
G80- Limited Slip
G92- Performance rear axle ratio
J65- 4 Wheel Disk
LB9- 305 TPI H.O.
MK6- Manual 5 speed, 2.95 First, OD
MM5- Manual trans provisions
KC4- Engine oil cooler

I have researched as much as I can, and I cannot find much info about the '88 production. Any help would be appreciated, I have heard that this combo of performace options is rare but I would like to know the exact #'s.

 

You won't get a break down of the options like you want. The options listed are the go-fast options available. Sounds like the person that ordered the car knew what they wanted. Without the G92 code, you got the 3.08 gears. Adding the G92 gave you the other performance goodies as mandatory requirements. The fact that the car is also a hard top tells me that the original owner bought the car to play! The 3.45 gears was the tallest available in 88. The auto would have given you 3.27. Sounds like a nice car in a color that I want and with the goodies I want.

 

From what I have been able to gather is that the car was a owned/used by GM (probally a Excutive car) for the first year. So, GM themselves ordered it. Then it was sold to the general manager of a local dealership who was the offical first owner in May of 1989. In a roundabout way I bought the car from them this summer, so I am the 2nd owner....not counting GM.