heads
241s whill lower the compression, but have bigger valves. the flow is probably too close to really make much of a difference.
BUT
if the 241s have been ported and milled...you could gain nicely. on a stock engine you could still see 20hp...possibly more depending on how worked the heads are.
i would leave the truck intake on. it has been shown to flow similar to the ls6, except in the upper rpm i think. after all it was designed to make power down low.
ls1 would be a downgrade

