Edelbrock used to make a "street Master 318" intake I had one on my 79 D 100 shortbed, which I had put in a 69 318 in (higher CR because the 69 heads had smaller chambers) and like the smallest Purple shaft MP cam (P/N ended in 757) with a Carter AFB 625 CFM that thing ran GREAT and pulled down some surprising MPG numbers too; (22+ on the hwy)
and I didn't drive that thing easy either; maybe it was the lack of power steering power brakes and the fact that it was a 833 OD. I was actually QUITE hard on that truck!!!!