Well, the limited budget says a set of 360 heads will fit the pocket. The larger head window will give the car a lazy bottom end. It'll pick up once your at speed.
Porting a set of 302's is a catch 22. If you can do it, then being without money is something your not.
A good cheaper compromise is a Magnum head. The added rocker ratio will add intensicty to the cam with more lift. The smaller head chamber will keep compresion up. Use with a .040 (Or close as possible) head gasket and a dual plane intake.
Resell what doesn't fit the Magnum head set up and get what you need. Exchange brand new parts for the correct ones needed.
(Lifters, springs and anything else.)