Go with the Genesis or better yet, a Pond aluminum block. Stroke the snot outta the puppy (4.25" to 4.375"). Get some aluminum (Ebok or Blue Thunder) CNC'd BIG port heads. There's some new off shore forged 4340 moly cranks out there that when prep'd well make for a bullet proof bottom end. They're about the same price as the Scat stuff too. Round it out with some Diamond pistons and a big mutha of a hydraulic roller. Hang a set of Mickey Thompson ET Street drag radials on the back (what I run) and start looking for those displacement deficient, wimpy, underpowered 500 HP 427 side oilers to biatch slap around.
I can cruise all day at 1800 rpm and yank daylight under the fronts on a launch when I need to. My vote is.... 650HP, or bust.
Dave