my 408 bored .060 with 12:1 comp would make 373hp/480ftlb tq averaged thru 6500/5500 and the 427 with 12:1 would be 376/491 averaged 6500/5500,so looks like the 427 would be a tad better.

http://www.youtube.com/watch?v=aIxaesJ190U

http://youtu.be/lCZAaN7fFLg