I am new here and this is my first post. My plan is to build a 4bt for the best possible highway MPG. I plan to use a 64 IHC short bed 1/2 ton. I have rebuilt the frame with the larger (12 in brakes) and rebuilt the springs from a heavy duty 1/2 ton IHC. Belive it or not the IHC V-8s were very heavy 778lb for the 266, 780lb for the 304, and 803lb for the 345. So I think the truck will handle the weight OK. I plan to use a Dodge NV4500 and my IHC Dana 44 with 3.54 or 3.25 gears in it and 29in tall tires. This will be a 2wd truck. Do you guys think the Dana 44 will be up to the task? Will a 9in Ford be a better choice? Not sure of the weight of this truck but suppose its about the same as any 1/2 ton of that era. What is the best model of 4bt for me to be looking for? What do you think my MPG might be at 65 to 70 mph? (i know that may be a loaded question). Any advice form you guys will be appreciated.