85 Chevy 350 Conversion Van Overheats):

Definitely replaced the thermostat. Am eying the water pump. Hoping it's that simple. I do question my backyard mechanic decision, but needs must as the devil drives, and in my defense, she does drive now. I'm thinking about just storing it til I can get the money for a real shop. I definitely don't want anything more modern tho. I've taken her to several mechanix and everyone crushes on her immediately(: It's a great van, perfect size, awesome engine once i get her fuel injected and rip out and burn whatever the loser I bought it from did to it. I don't know what I'm looking for one here I guess. Does anyone have a similar rv that may have seen this before? Or just heard this problem before? So many things can go wrong with any engine. I specifically wanted one with few electrix and lots of lego pieces that were easy to find.
Would the air conditioning belt and smog system being missing be a cause for any of this?