W2 heads

So what you're saying is just buy the new ones that are available and like RRR and Wyrm said get the long valves if going with a big cam, I would assume chambers should be closed for quench purposes as well. I'm comfortable setting up big blocks (Heck last year did A 451 with 12" vaccum go 612hp 625tq) but the small blocks I'm not sure that's why I ask people that know better. There just are so many

You need to get the long valve HEADS. The heads are cast differently to handle longer valves.

I never could for the life of me figure out WHY Mopar made badass heads for the small block and made a stock valve length head. Most anyone using W2s would go for a camshaft big enough to need a spring that the stock length valve could not handle.