Still looking? You can make great horsepower out of the cast iron block. I did a 408 stroker last year with stock heads and intake, it 400 at the rear wheels no problem at the dyno. There was a lot more there if management would have let have my way. They only had a base tune done it also. Let me know, I know built well over a 100 LS 1,2,6,7 & lsa.