The best bang for the buck in iron heads will be the Chevy L31 Vortec units part # 12558060 for $249.75 each at Scoggin-Dickey. That part number will get you heads that will allow a maximum lift of 0.450", but they also offer heads that have been modified for higher lift. Part # SD8060AGP has been modified for 0.525" lift and is machined for screw-in studs and guide plates (not included) $388.25 each. www.SDPC2000.com

The cam you use will be the limiting factor in revs. The little 283's will spin up pretty tight, particularly with good rods and aftermarket 4-bolt main caps. You'll run out of cam before you run out of crank