Why?

Just read this article. I think you would be hard pressed to build a big block with stock heads and make this power. Reason I say stock heads is because that's what is used on this hemi build.
http://www.moparmusclemagazine.com/...can_you_hear_the_hemi_now_part_1/viewall.html
http://www.moparmusclemagazine.com/...opp_1304_can_you_hemi_now_part_2/viewall.html