Kirk, I have a 48 3600, I put a 1/2 ton axle, from a 52 3100 under the front (the 3/4 ton and 1/2 ton front springs are the same). The rear springs are different between 3/4 ton and 1/2 ton. My 48 had helper springs on the rear. I removed them but left the other springs in place. I put a 1/2 ton rear end from a 64 C10 (3:73 gears) under my 3600. Now I have six lugs front and back with newer brakes and a better gear ratio. I have not noticed any significant difference in the height of the truck....I like the original height too. I now consider my truck a "heavy-half" ton. Scott
