Overheating Issues!

i know nothing about timing. and not sure what its at right now. my dad checked the timing a while back when I first got the car, and said that it was right on though.

I am running stock fan. no shroud though. Thinking about getting an electric fan, but I want to fix whatever problem I am having first. I dont want to "mask up" my problem by throwing a new fan in there before figuring out why it started running hotter in the first place. I'm also thinking maybe It could be the radiator. and was going to try flushing it this weekend, but wanted to get some other suggestions first as well