okay the same prob my car overheats. It would usually run 210 in the day and about 185 at night but it started to overheat last week. I thougth it was my rad since its old and it had a small leak but this is where it gets confusing. I bought a aluminum 1 core at auto zone and put a 160* thermo in since I have a hypertech chip, and they said if you live in a hot climate it would be the right choice. Oh I live in phoenix AZ. All that didnt work so I thought it may be my water pump, replaced that no difference. Im stuck now and I think the one core rad isint good enough since I had a three core in it before. Auto zone has a three core metal and I was thinking that may be the right choice. Car runs good dont think its a bad head gasket but you never know. Oh yeah the temp will reach 250+. fan is hard wired also. some advice please.

 

Always replace the Radiator with the same size or larger, never get a smaller (or fewer core) Radiator than what originally came with the engine especially if you live in Arizona.