Unfortunately, the T-case from an F150 is drivers side drop so no swapping there. With a 4.696 1st gear and a .636 overdrive, with some decent diff gears low range may not be needed. Rock crawling in a van just seems like a bad idea.
With 33" tires and 5.0 gears it would do about 25MPH at...
Ahhhhhh, my SW skills are more than a little rusty. Quick google cheat shows you can convert them to sheet metal parts pretty easy and joining them isn't much harder. The K factor .447
A good shop will know if you have screwed the pooch on anything and call you about it.
When My buddy Craig...
Where are you located? The sheetmetal shop I used in SoCal would laser cut parts and break them for a pretty reasonable price.
They do a LOT of parts for a lot of off-road shops in the SoCal area. Getting a knock down kit from them is pretty easy. Having a few bends in...
The closer you can get to zero preload, the better off you will be. Shock tower brace is an excellent idea.
Are there any parts like the "frame rails", shock towers or the cross members that you could bend and combine 2 parts? It would cut down on assembly time quite a bit.
If you went King's (bro), they have an over the body top cap which reduces the body length by an inch or so. You can also get a longer shaft with a welded eyelet that will clear the axle.
If your going custom on the shocks, Kings take about half the time to get over Fox's.
I believe JD fab...
Toyotas have boxed welded frames which are not heat treated.
Ford's have C section heat treated frames.
Do not weld on the Ford frame unless you want a whole bunch of cracks.
Bolt it on with 3 mounting points. 2 by the cab and one in the center in the rear to deal with the frame flex.
You would be much better off moving the lower shock mount out and making a new shock tower to fit a longer shock. Your motion ratio is pretty close to 2-1. This will be really hard on the shock. Also with springs that heavy you will run into coil bind issues. 2.0's witth that much load on them...