I have a mild 440 and have driven friends SRT8 6.1's. (Yeah, I know, not a 6.4)

Totally different animals!

Personally? I like the brutal torque of a mildly modified 440/500.

If you're doing a B or RB go with the biggest stroke you can (500+) and Indy EZ heads. You will have more power than you can use in a very mild package. To me, anything over 550 HP on the street is silly anyway.

Ron's combination is perfect for a street/strip car IMO!

Oh yeah, Ive used the solid .528 cam and absolutely loved it in a 440 urged '71 Cuda.