Chevy never made a 1986 IROC-Z convertible, not till '87 - so the answer is no.
Depends on engine...
No
If it's an automatic it's probably the 700R4
Too much... for what?
yes
It was just an incorporation of the "Z" in Z-28. IROC stood for International Race Of Champions.....from the Nascar IROC races.
Yes, they did iroc and Z28's are a little different, but i have just a regular Z28 most iroc's a tombport as regular Z28's do not.
no, all IROC-Z's were V8s.
the last production year for the iroc z was 1990, there is no such thing as a 1991 iroc z
the stock engine for an iroc z is 5.7 ltr v8 tpi with 220-230 hp. i know ive been driving one since 86 when i bought it new.
Check to make sure you are getting fuel and spark