Like Wart1de, I also don't have any personal experience with these yet, but I've heard nothing but great things about these heads and if I don't use a set of original heads on my 340 build I'll be going with a pair of the RHS heads. They help with compression and flow better/or at least as good as almost any of the other aftermarket heads. The only reason I might not go with them is that I may be sticking with stock appearing parts externally including stock exhaust manifolds.
Search for other threads on these heads, you'll see lots of positive comments.
Later, Jim
