I've used this forum for years to find any info I ever needed, so I never had to post. This is the question: Will my 88 iroc-z 305 TPI and 700-4R run with absolutely not touching the ecm and no prom burning if i install 10239906 vortec heads and a gen. II Camaro LT1 350 factory stock cam? And, will it pass california smog test? Should I mill the vortecs to bring them down from 64cc to the 58cc the iroc heads have or should i leave the vortecs alone and just bolt them on as is? or.. stock rebuild with stock iroc heads with that Gen 2 Camaro LT1 350 cam? My engine finally got some rod knock so its time to rebuild, I have that engine in the car. I have those vortec heads in my garage. And I have a buddy with the scoggy dickens tpi base to vortec heads to make it all happen that he never used and i can have that base. Any advice or opinions are welcome, who's done this setup? Thank you everybody.

 

From the smog test perspective I dont believe that vortec heads work with the stock EGR setup. I could be wrong but something to look into. There are other ways of getting that hooked up such as running tubes from your headders or exhaust manifold. There are a few post on here for how to do that. Smog test will likely fail with out it though. As far as milling the heads, why dont you just leave them as is and go with flat top pistons if you are rebuilding? For the Prom it may work as is but you will not get all the benefits of the changes you are making.

 

That setup is perfectly legal in California. I ran it on mine for a couple years. The only thing you are changing is the base and the heads. Retain all other components and put a blockoff plate.on the rearmost egr port (that port is used on vettes). All else will bolt up fine. A tune is recommended to take full.advantage of better flowing heads and a more powerful cam. Milling the heads is not necessary.

 

Corvettes got the Aluminum L98 heads with 58cc chambers, our F body L98 heads are Iron, and have 64cc chambers like the vortecs. No need to mill.

My stock 89 ECM/tune, with a ZZ4 cam passed North Carolina tailpipe sniffer. Quite certain Cali is much worse. The car was giving up some performance I'm sure, but it ran flawlessly. I planned to get it tuned, which I have since done, but it ran great.