When it comes to budget building... sometimes the best approach is to just buy a 160 dollar set of pistons and rings, have the block done, polish the crank and put some cheapo bearings in. Ring seal is where the power and longevity lies.
Buy all that stuff like an intake and carburetor... and headers ...and cam and lifters, and you realize you could build a bottom end already...
Best budget motor I ever ran was a 318 I found in a junkyard that someone had done the bottom end, some cheap-o pistons and ground the crank. I pulled it out tore the 360 heads off of it and brought it home, it was never even run...
I slapped a used set of 318 heads on it that had closed Chambers, stock 340 cam, and an eddy performer I also found in the junk yard for 25 bucks and ran it.... it ran hard to 5800 rpm.
I tried that same **** with a used 318 one time that had about 115 to 120 PSI....it was "soft as **** after taking a laxative" and burnt oil.
I'd almost rather have a fresh stock 318 than a used one with bolt on' s and a cam. Jmo