I am waiting for a iroc z to come to my local dealership from a town in the southern part of the state, its supposed to be in monday..they don't know what size the engine is or if its an auto or manual...or 305 tbi, 305tpi, or 350 tpi...I know if its a 350 its not a manual..What I want to know is what is the common engine found in the 1987 iroc z's..and how common are 5 speeds in the 305 models..

 

I Would think that the most common engine would Be the LB9.
But according to the Brochure.. the LG4 5.0 4Bbl carb was the standard engine. The LB9 was optional. a standard transmission was standard.. the Auto was Optional.

 

thanks