Direct Connection Purple Shaft cams are biased toward the drag race crowd, and they're not a good choice if you're planning to build a street machine. I built 440 and 426 hemi-based truck pull engines for several years, including a bored-out hemi that ended up at 547 cubic inches after filling the cooling system with epoxy and boring all the way through the cylinder walls in places to accommodate big flanged sleeves. We didn't even fire that engine up until after we towed the truck onto the pull track with a 4WD tug and hooked it up to the sled. No dyno runs, but we were estimating 1200+ HP on an alcohol/nitromethane mixture and fuel injection.
I'd suggest the Comp Cams Magnum series camshafts, in the 270 to 300 degree duration range. You'll need the compression bumped up to 10:1 or so, and a torque converter with a 2500 RPM stall speed or slightly above, or a stick shift transmission. Do a little pocket porting on the heads and a good 3-angle valve job. Top it off with a dual plane intake and a 700 CFM Carter AFB or the Edelbrock clone. (An old Carter is better!) Use stock cast iron exhaust manifolds unless you really love changing header gaskets every few weeks. You'll have some tire-smoking torque, and a reasonably street-friendly idle with a pretty good lope, but not so much to make it annoying to drive.
Jerry
