Yes a second gen radiator will fit, but you may have to tap in the bottom edges a little. I had an 86 parts truck from arizona desert and it had a big 3 row aftermarket radiator. Only mod I had to do to fit my 80 was tap in the bottom corners a little and it fit great, but the shroud wouldn't fit anymore. Don't do like me though, I had it tested then tapped in the corners, then had to have it tested again. Helps to run a couple of pieces of cut radiator hose between the radiator and frame, led to fix #3.
