I agree with JoeH. Sooner or later the old one will get you. I drove mine using original for several years with 4lb pressure cap but it gave up about 2 years ago. The local shop back then wanted $547 to redo mine. Soooo, I bought me a new aftermarket aluminum, at that time for $250 and it had the tranny cooler in the bottom and now I run a 7lb cap and have never had a moments problem out of it.
Oh, when the guy quoted me $547 understand my core was super nice and was NEW core when I built my 37.... all I wanted him to do was change the tanks which he had that would fit!!! I laughed out loud in front of him and layed the radiator back in my pickup. Maybe his girlfriend needed some money???
