A 450 hp 400 is easy and could be done for less than $4500, including e-heads. That motor would also have forged KB pistons and Tomahawk 5140 rods, PRW stainless roller rockers, etc.so it would be reliable. But for $4k you could also build a 400/462 stroker capped w/ ported 6x-8's or 6x-4's and make 475-500 hp and 525 ft/lbs.
The budget 462 stroker would be plenty of motor- you'll need some wide slicks or drag radials on 17 x 11's to hook up with that much power on tap. It's nice to fantasize about all aluminum 540's making 750+ hp, but in reality an aluminum headed, 550-575 hp 462 stroker is overkill, unless you run the Silver State Classic on a regular basis.
Geno