I JUST BOUGHT A 98 D2500 4 WD WITH CUMMINS AND 5 SPEED TRANS. IT HAS 2 DIFFERENT SIZE TIRES FROM FRONT TO BACK. I THINK IT WILL PROBLY DAMAGE THE TRANSFER CASE IF I USE 4 WD. CAN ANYONE TELL ME IF I AM RITE??? TIRES ARE ABOUT 1 INCH DIFFERENCE IN SIZE. TRANKS JIM!!