[WSSix]

I thought a pair of complete L92 heads was only like $1200 from GMPP? If that's the case, you'd only be saving yourself a small amount but it's still a savings. Sodium filled valves aren't worth the money in my opinion. Their advantages don't out weight the costs involved.

In general, the L92/LS3 heads are great heads to have. If you can get them for a good price, they are a good start and have plenty of room to grow. If money is kind of tight and the power goals are reasonable, LQ9 or LS6 heads will do very well for you also. They should come in less overall cost wise because you don't have to buy a new intake or intake rocker arms.

Gen 4 cam doesn't swap directly with Gen 3 engines. Keep the cam, block, and PCM the same generation. Unless you want VVT, Gen 4 doesn't offer an advantage over Gen 3.