I am looking at two tranny coolers from Jegs,which is the best choice for my application,B&M 70266 (28,000 GVW, 20,500 BTU 11"x8"x1"1/2) or B&M 70274 (29,200 GVW, 29,200 BTU 11"x11"x 1"1/2). I will be running it in series with the internal cooler,mounting it behind the grill,the radiator is a aluminum GN1 stock replacement with stock GN fan assembly. I just updated the stock D5 for a PTC 10" LU 2800 stall. Thanks, Kyle.