How much difference is there between the 47-54 1/2, 3/4, and 1.5 ton trucks? IE: frame diamentions, cabs, fenders etc. I poked my head under the 50 GMC 1.5T I have and was surprised at how small the springs and frame sections were (front and rear ends. middle looked beefy). The front axle definately wasn't as big as I thought it would be. The brakes were large as was the rear diff. It has 20" rims on it. so I was just wondering what was different. Thanks in advance.