Real differences between 2500\'s vs 3500 Trying to find the acutal differences between the two, but so far, Im comming up with not too much. Cab/frame/body= seems the same from what I could find. Brakes= I believe the 3500 had bigger brakes-But I cant seem to find if they are different on the front. Rear brakes are only different if it was a 14bSF vs 14bFF and dually drum brakes were bigger. Engine- The engine/tranny combo's looked identical between the two. No special choices for one vs the other. Tire Size: I think the 3500's got 245 standard, and the 2500's were getting something slightly smaller standard.