Not a reliable method for model identification. Just as Bad as the square shift **** for certain engines options.

 

Unfortinatly that has been removed from my car so i have no way of finding out! i will just assume that it is a z28 but it is just a little strange to me! There is a couple of codes underneath my hood so ill look through some codes to see what those mean! My speedo is only up too 85 so if that is the way to tell then i absolutly have a z! either way it dosent matter the car is still great!

 

I didn't catch it earlier, but you said you had a 86 Z with the 305 TBI, well, that can't be unless someone put the TBI on there. You should either have TPI or hopefully one of the carb motors which will make swapping in the HO much easier, less headaches with the fuel pump, etc...

What is making you think it's an IROC, the Z28 and IROC had the same hood, same ground effects, etc. Visibly, the IROC only had a different pin-stripe package with the IROC door decals and optional 16 inch rims... You can easily tell by looking at the front of the dash right in front of the passenger seat, an 86 should have a large Z28 badge with IROC-Z right underneath it, at least my 86 does....