318 budget build help?

If you get a good engine, (ie doesn't need a rebuild) I'd start by fitting a four barrel manifold and carb (like an edelbrock performer, or an LD4B if you can find one at the right price) And a set of headers. If your budget can stretch that far, fit a cam like a comp XE 262. It's a fairly low buck mod to port the heads like in Justin's thread "318 head porting for the average Joe"
Or if you can get a good running 360 for cheap, throw it in. Nothing wrong with a 318 though. But bang for buck a 360 will yeild more for less coin. People on here say that they're cheap as to buy. (They certainly aren't cheap or plentiful where I live)