86 K1500 Suburban radiator
 

I am doin heads,intake and carb on my 86 Bourbon. Old radiator is too far gone to save. It is a 3 row, so I ordered an aluminum Frostbite (Holley) from Jegs. It is too thick and won't fit the mounts. They claim stock fitment, but they are at least 1/2 inch too wide.
I don't think I want a plastic tank radiator. Am I wrong? Any suggestions as to a decent radiator for this truck???