A 350 V8 at 4K is just loafing along- - - -I've built plenty of them that live comfortably at 7K on the round tracks. Just match the camshaft and valve system to the speed you want to run. I'd reccomend a Comp Cams 260H RV cam and springs that will allow operation without valve float up to 6K RPM or so. Use about 9:1 compression and regular gas. The RV cam has a pretty flat torque curve that begins to produce usable torque in the 1800-2K range, and HP that tops out just under 5K. Perfect for hauling heavy loads on long upgrades.
Jerry


"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!