Hello- I have an 86 Z28 with the 5.0 (HO I think) 4 brl. I've seen a few Iroc's claiming to be true Irocs that have the same motor? I thought the major diff was the true Iroc had to be a tpi?

Also- what would it take to actually make a z28 into an iroc and how hard is it to swap out the carb and install the TPI. For the novice wrench-turner- is it someone feasable? I assume the computer, intake, tpi and distributor would have to be swapped- the fuel line as well?

 

From 85 to 87, the base engine in the Z28 and the IROC was the carbureted LG4. The TPI was the optional engine. From 88 to 89, the base engine was the L03 TBI. TPI was still the optional engine. In 90-92, TPI was the base engine, with 305 being standard, and 350 being optional.

I doubt you have the H.O., because they were very rare for '86. Do you have a dual snorkel air cleaner? Is the 8th digit of your VIN number a G? An H means its the LG4.

The biggest difference in a Z28 to an IROC is the suspension. Wonderbar, shocks, springs, sway bars, and 16" wheels on the IROC. Swapping carb to TPI is about an 8 out of 10 in my opinion. Not something a first time mechanic would want to do.

 

Swapping from carb to TPI/EFI is not hard with the right manuals, but it is pretty time consuming.