Wrong choice for my 76 Duster's radiator replacement?

I run a Cold Case. I like it better than my 3 core Champion. Any large 2 core or small 3 or 4 core radiators have a core that is thicker then stock and presents some sealing issues with the factory shroud and whichever fan spacer be it solid or thermostatic will be too long. My 340 is far from stock and at .060 over the Cold Case keeps it at 180f.