[WSSix]

Ron, it's purely a budget reason I don't recommend sodium filled valves right off the bat. They are superior but they aren't needed. Regular valves last a long time as well and the engines that run them perform just fine. LS2 heads are the same as LS6 heads but they don't have sodium filled valves.

Monte, I'd go for the L92 heads since you already have the other parts needed for the most part. You'll need an adapter to control the L92 throttle body or have your harness built with the correct connector. Same with the injector connectors. The stock GM offset rocker arms aren't expensive and work just fine. At this point, it'll only cost a little more to complete the conversion versus staying with a Gen 3 top end. The L92 stuff is superior so in the future you'll be able to expand your power production.

Go with 1-7/8 inch headers now unless you already have or find a great deal on 1-3/4 headers. I say this because you won't be giving up much going with the bigger headers now and they will support ported heads later.

Also, putting a 4in crank in the engine is cheap, easy, and when matched with the L92 heads will easily put 500hp to the wheels with great torque as well. That was the plan for my TA before I totaled my LT1 Formula. I'm still going back to that plan should putting turbos on the LT1 not work out.