Andy,
I'm currently converting a 1959 3800 (one ton) to 4x4 dually
I've got a Dana 60 front axle from a 1987 Chev P/U and a Dana 70 rear axle form a 1992 Chev P-30 van. The Dana 60 will bolt up the the original leaf springs out front (same spacing) while the Dana 70 will require moving the spring perches in a little (I could have used a narrower rear end, but did not want to cut the sides of my box). I'll probably have to use 3" spacers between the rear axle and springs to raise the rear of the truck to level it out.
I plan on mounting a NP-205 Transfer Case (gear drive) to power the front axle. I'm using the original frame (after reinforcing it).
I don't have any recent pictures, but plan on taking some shortly as I proceed. PM me for more information.
Lane
