Alright I'm not the 3rd generation enthusiast I want to be yet so don't give me any crap for this question please. I've looked at the '90 tech page but I think it may need some revision because a little of it didn't make sense to me but, my question is: as far as the body and interior go, what are the differences between the 1990 IROC-Z and RS? The more elaborate, the more helpful. Thanks!

 

One thing I know the Iroc will have is the 145MPH speedo.
The RS will have 110 I think.

I'm also not sure, but were the foglights an option on the RS?

 

as far as body and interior ONLY, would be grill, hood, badges (int&ext), decals, tail lights, headlight bucket paint, wheels, speedometer...just visual

 

I have a 86 iroc z28 and the spedometer reads 85 mph.

 

Was it ever switched out i believe the 145 gauge was standard on the iroc

 

The parts id card in the center console has the code "b4z" and "z28" and the vin matches the title, so it is a true iroc.

 

Guys, an '86 doesn't have anything to do with the 1990 the OP is asking about. The '86 cars came with 85mph speedometers due to federal regulations. Part way through '86, they switched to the higher speedometers. Not all IROC-Zs have the 145 speedo.

As was mentioned, the majority of the difference is cosmetic/appearance. The IROC-Z had better engine options, but could also have the same L03 that the RS could have. The IROC-Z also has better handling and suspension over the RS.

 

Best answer would be, The IROC cost more money then the RS when new. It also was the top of the line model (IROC).

 

Well said Scott!

Mine is a true iroc z28 with the code reading "b4Z" in the center console and my speedo reads 85 mph.