Cheap 318 performance mods.

4bbl manifold, pretty much any dual plane (even factory!) and a 600~650 carb along with headers and a good ignition curve will do wonders.

if you have 302 heads and they require very little investment, then sure, why not. if you don't have 302 heads, there are better options. any of the "small valve" 360 heads would be good.

the key here is to find some that are in great condition, otherwise you're spending $$ for something mediocre, and that $$ would be better spent on good aftermarket heads. or magnums if you wanna roll that way.

if you do the cam, keep it small. the range that @318willrun posted upthread is a great guide.