$ Building a Slant 6 for performance

All that said, I'm not building a race truck by any means. But I definitely need for it to be able to get out of it's own way. Which it don't do now.
HP wise, I hope to get at least in between what a stock for 1985 318 and a stock for 1985 360 out of my slant, so that would put it at 140-150 hp. At a minimum. A high (for a slant) revving version wouldn't be very suited to a truck that was built with a front end that resembles a brick wall.
My basis for my build is a 74 forged crank bottom end and an early (as peanut heads are concerned) peanut head, without all of the extra holes for the AIR pump.