Why is the Deuce running Hot 

You need to flush your coolant system. I had to pull the radiator on mine and flush it thoughly. Once flushed properly, fill the system and let it run with the cap off to purge out all the air. Air pockets will cause over heating

First thing I did on my 5 ton was drain the entire system intl 5 gallon buckets and that coolant was nasty. Fixed my hotter temperatures though

Your truck is a '71 and so is your WIFE who is most certainly not 60 something 😂❤