Nah, if it comes down to slopping some kind of goo on there, I'm gonna just buy one. Solder I don't mind but Mighty Putty, JB, etc. ain't happenin'.
Ok, the holes are soldered. It seems the top four tubes each developed a tiny crack where they attach to the passenger side tank, probably stress cracks from tools being laid down on the radiator, or me leaning over it when I changed the water pump, who knows? I will run it for a week or so to make sure it holds, will borrow a pressure tester tomorrow and see what happens. I'm confident I did the best repair I could, so if this doesn't work I'll be buying a radiator...
I just ordered a Champion radiator today - for the Muskrat - not for any of my Mavericks. Its a three row radiator that is fully guaranteed or my money back and part of the guarantee is that it will cool engines to 650HP - that should be enough. $200 with shipping and handling. I'm looking forward to getting it and making my fan shroud to fit it and my fan.
