I may have it fixed. I topped off the radiator and ran it up to temp and it didn't appear to be going above normal. So I went for a little trip up to the Fire Station and borrowed a laser thermometer and checked everything. It agreed with the temp gauge where it goes into the head. The top of the rad was about 180-185 and bottom was running 155-165, hard to get a good reading down there with it running.
I did notice that there appear to be some coolant leaking out around the rad cap so I first thought I should replace it. So while I was looking up the part number of the last one I bought in my receipts I found out its a 4 PSI. Should I be able to run a 7 PSI cap? This is still the original Harrison radiator from a 52 3100.
