I have a 74 F250 that I have highly modified. It started as a normal standard cab 8ft bed 4x4. It now is an extended cab with a 79 Bronco rear clip. 428CJ
4 spd. killed the dana 60 and replaced it with a 70 with 4.56 posi. I am planning to set it up with two transfer cases, one married and one divorced.
My question here is; I have a front axle assy from a 2005 Super duty that I am considering. I was going to try to use F150 coil mounts and springs. Obviously I will change the front gears to match the rears. What you think?

 

Dont see why that would not work, except that the SD frame was wider than the early ford truck, so even if you use any spring bucket and attach to the frame, the springs will still be in the wrong spot, but the concept is nice.
While I am all for the larger D60 front axle, I am not a big fan of the unit bearing design for these front axles, and might re-consider the use of this axle, but all in all, the concept is a creative idea.
Have you considered a coilover and 4-link? You will have your hands full with fabrication anyway, so as long as your are at it, why not take it a step further?
Link suspensions are available for the SD trucks, and will bolt up to the axle. This should limit fabrication at the axle itself, and then you would only have to fab up new mounts for the frame, or modify the SD mounts to fit your early chassis.
You will also be limited to an inverted "t" type steering, since this is what type of steering the SD axle has, and the knuckle does not have provisions for a crossover without a new knuckle. Trac bar is probably the easiest part to modify here.
If your steering has not beem nodified yet, and you are still running the original power assist, you will need a new box.
Your idea of two T-cases is not new, but the divorced, and married concept is. Which boxes are you planning on using for this? Is this just so you can obtain a 4:1 low ratio?
Are you planning on running the 203.205 combo? The married and divorced cases confuse me a little. Thinking that would make for a crazy long front drive shaft, and a rather short rear one.
I use this kit, and have been pleased.
http://www.northwestfab.com/203-205adaptor.html

Trying to run "series t-cases" sometime present some problems, especially with shifters, and linkages, where this kit keeps the package rather small.
Cool idea, would like to see that come together.

 

What, no pictures? We need pictures! Sounds like a nice project.

 

I originally "built" this thing back about 1984 from a 74 F250 std cab 8'bed truck. I used an 78 extended cab with the back half of a 79 Bronco welded on. A buddy made me welded boxing for the frame to fit the two bodies and the frame together with no lift blocks. I opened the back of the cab and fitted it with seats for 8 people. Built me a mean 428cj,780 holley, ceramic clutch etc. Im running 39.5 Gumbo mudders on 15x10 8 bolt old school white spokes. cant count how many u joints and driveshafts i destroyed before I got the right combinations to stop that. Then one evening I was showing off and twisted the Dana 60 pinion shaft in 2 pcs. Now it has a 70. Right now I am in the planning stages of this super duty/dual transfer case and possible dual wheeled setup and am trying to get as many ideas as possible before I get down to the actual modifications. I want to get it runnable, but it probably wont be legal, but I would like to take it to Carlisle all truck in August even if I have to tow it there with my Powerstroke.

 

Post some pictures! I went to Carlisle all Ford Nationals the last two years and went to the All Truck Show last year. There was all kinds of good stuff there & a swap meet full of 73-79 ford parts. However, there was a couple trucks that I couldn't believe people were actually showing. I'm sure I'll be able to tell if you are there if I go.

TheBlueMule

 

I agree I would love to see what that rig looks like sounds like a cool concept!!!
PICS Please!!