I drive a lot in the desert areas around here, and am stuck in traffic on a daily basis. If I get the dual core I will ditch the 185* t-stat. they don't really keep it cooler, but do a better job at cooling by seperating the hot and cooler fluids.

 

i was studying this awhile back. the 1500 is the narrow size and only 1 row. the diesel is the wider size and is 2 rows. the 2500 body can have either engine, so i think it will fit fine, but you'll need reducers for the hoses. measure the tube sizes from each, and find the appropriate reducers. ebay has them cheap.

post back what you do, this could be a good mod for adding a lot of extra cooling capacity for towing. (right before the transmission goes out).

 

Do these convert, I failed at math.

31-5/8 x 19-3/8 x 1-1/4 this is for the dual core from rad express

31.62 in. x 19.37 in. x 1.25 in. core size, 1.5 in. inlet size, 1.75 in. outlet size, 2-1/2 in. x 20-1/4 in. top header, 2-1/2 in. x 20-1/4 in. bottom header, plastic tanks, top left This is from Carjunky saying direct replcement and 2 dollars cheaper with free shipping.