Hello i own a 88 Iroc-z & I'm having a little trouble identifying if i have a 305 or 350 motor, is there a way to tell? Any help would be appreciated thank you.

 

That information would be embedded in your car's VIN number.

Google a VIN Decoder or try one of these:
http://www.iroc-ss.com/vin.htm
http://www.decodethis.com/Default.as...FP21E7JL172336

The eighth (8th) letter/number should give you the engine type.

 

Is it original? If so what is the 8th digit in the VIN, that will tell you. If its not original you’ll need to find the number stamped on the front pad on the block, If that’s not there you have to start finding the casting numbers but that may not always be right.

 

^^Thank you so much! The reason i asked was because i recently purchased an EGR valve for my engine sz & it did not fit so insted i orderd one for the 305 wich is exactly i dentical bu i was worried it might not wrok.

 

Not directly mentioned yet . . . the VIN's eighth digit . . .
F = 305 (5.0L TPI - RPO LB9)
8 = 350 (5.7L TPI - RPO L98)
. . . as it would have came from the factory (nothing changed since).
If not sure if it's original, as mentioned above, the block's casting # is the only sure way of knowing.

 

To add to Iroctopless' and Wildjeff's info does the motor in your IROC have TPI or TBI induction?If TBI it could be the LO3 305(VIN eighth digit E) which was the base motor for the IROC in '88.

 

If you have to take off a large plenum to get to your EGR then you have TPI, if the EGR is easier to get to like remove the air filter and its right there then you have an LO3 305.

THe LO3 looks like a Carburated car with the aircleaner on, I think they may have actually used the same lid as the 87 LG4's. The TPI looks like a scorpion sitting on your engine, 8 legs & all...

 

Yes sir it's the original engine, thank you Iroctopless the eight digit is an 8 so i guess i have the 350. Okfoz i did have to remove the plenum & it was a pain in the butt lol.