New to site, new to Mopar overheating issues

I'm going to check all of these things starting with cleaning rad, checking the thermo, getting the right fan and possibly shroud and clutch. I might just go ahead and pull off the pump as well to see what blade it is. My guess is that the previous owners were having cooling issues, wired on an electric fan and thought.... done. Always amazes me how someone can do things to these beauties without doing their research.
I must ask, do you know for sure how warm it is getting? Replace the cap if you can't have it tested.