Horsepower with mileage options

I wouldn't talk him out of the aluminum heads, but a 2bbl intake is a waste of space.
His money ? aluminum heads, camshaft in the 258 -268 range, dual plane intake with a holley 600.
FWIW 340 camshaft was designed for a little more compression than you have with a 2bbl 318.
I like a 258 @ 050 for the 318