65 galaxie electrical problem

My 65 galaxie 500 XL is giving me some problems with the ignition system. I was hoping someone could give me some more ideas. I traded the stock 390 for a 428cj a few years ago and have had no trouble til recently when it began to act up. It would start fine, but once I drove it any where and shut it off it would not re-start until about an hour or so later. Now its gotten to the point where it wont start but cranks real slow like its not got enough power to turn it over. So I put in a new battery, a new alternator, a new starter, and a new solenoid. Now the solenoid just clicks when I turn the key. If I try to jump or boost the battery I can sometimes get it to crank, but the battery cable and starter cable get really hot. I checked all my connections and my wiring diagram to make sure all is wired correct. I am out of ideas, anyone have any suggestions?

I'd start by checking to see if the engine is properly grounded.

Next I'd check or change the battery cables, make sure they are a heavy grade cable...those suto part store cables are usually marginal, then once they get a few years old they are toast.

It seems to me (with the hot cables, slow starter even after changing the battery) that electricity is not flowing properly.

do you still have tons of power everywere els? if not Sounds like your wireing from the battery to the solinoid I know you said you checked it but thats all i can think of. hope i helped Good luck