360 or 318

I've been looking for an engine to swap into my 1969 slant 6 dart. I wanted a 340, but as a high schooler I'd have a hard time affording one. I started looking for a running 360 donor car that I could pull everything out of, swap it in with some Schumacher mounts, and go. I'd bolt on a carb, manifold, and headers and maybe do a cam swap, figuring I'll do the heads later. Finding a 360 has been harder than I thought, but I keep stumbling across 318s. How much power could I get from simple bolt ons? Would it be a Worthwhile upgrade over the slant 6? Thanks in advance for all your opinions.