I'm no Chevy building expert, but I think one of the best stock heads out there are the Vortecs. They were used on a lot of cars over the years, but I think the best ones were from the late 90's (I may be corrected on this though) They use a different intake manifold bolt pattern, but if you are switching to a new intake anyway that shouldn't be a problem.

Next step up would be some steel heads like World Products, but these are going to set you back about $ 1000 a pair. Aluminum would be slightly more and would be the top of the food chain IMO.

The Vortecs, being the latest versions from GM, are superior to some of the older ones we rodders loved for years, like the double/camel hump 202's, etc. Aftermarket heads, even at a grand, are a pretty good deal compared to having stock heads reworked and rebuilt, and generally work so much better.

Now we will let the folks who really know this stuff tell us the straight scoop.

Don