I was wondering if a '86 305 out of an IROC Z28 is the same block as the 350? Most say it is but some say it's not. No one can give me any particulars either way. Anybody know what the differance is if there is one?...bolt patterns, oil journals, anything? Thanks, Cheers

Block is the same, stroke is different. Some of the "smog era" 305's had alternate heads, and alot of them came with additional CA pieces for getting through the California smog and efficiency rules. You can check the casting number or serial numbers and get the real skinny pretty quickly.

bill.

Try thirdgen.org, its a great site with lots of info.

Thanks guys. I'll check out both sugestions. I really appreciate the input. Cheers