You can move up to the 1.94 valve heads to make it breath a little better. My 283 still has the 1.72 intakes but I'm thinking of moving up. As far as a cam it kinda depends on alot of things. I have had good luck with the 327 cu in 350 hp cam in mine. I think it's discontinued at G.M. but is made by some aftermarket cam grinders.

Bob