[2002 zq8]

How much of a gain will port and polishing the heads do on the stock 4.3 heads. Is it worth it or are there aftermarket heads that anyone recommends that will still pass a smog test. I don't wanna raise compression too much cause I want to plan on a supercharger. If I have everything off for gaskets I was wondering if porting them would be a good thing at the time. Any views?

 

[foff667]

There are no 4.3 ltr heads availible and the stock castings arent bad but could use a good bowl job and possibly a 3 angle valve job with possibly larger valves...you will see more of an increase with a power adder ie blower/nos but u should see a gain of 2-5 tenths just with that one way or the other.

lata
Bill

 

[syclonedave]

Everything Bill said & maybe a bigger cam , don't raise comp. if your going blown. ( unless your going to run race gas all the time) Brodix might make some heads. Other than that all the usual stuff. $$$$$$

 

[964pt3]

I dont know about the emissions part, but they do make Splayed valve heads for the 4.3, run about $3800 . And Brodix makes them.