I probably should have posted more details on the setup. Car has an A500 in it with a 2400 TCI lockup converter.

Seeing as how I live in Michigan then I'll definitely leave the stock cooler inline.

Is it harder to flush the stacked plate coolers? I was just going to run mineral spirits through it with a couple of pounds from a blow gun behind it. I figured I'd do that until the mineral spirits came out clean on the other end.