87 14 bs/f swap

[The Intimidator]

I have got the new axle The gears are the same and breaks should be fine for a couple more months much better then the metal on metal breaks on the truck now. I was wondering what I need to change modify or break to get this new axle on it came from a 90 half ton chevy 4x4. I was also wondering if the leafsprings from the 90 will fit on the 87 they are a heavy leaf pack vs the stock half ton on the 87 should make the truck sit nice and level with a load of rock in the bed or a trailer hitched up.

The things I can see being a problem with this swap is,

The u-joint will I need a conversion unit?

Driveshaft length will my stock one be long enough or short enough to clear the new axle?

Spring perches will these need to be moved if so not a big deal but how do I line them both up and keep proper pinion angle while doing it?

Thanks my plan is to eventually (when money permit's) run 4.56 gears a detroit rear and a arb type locker up front with some other mod's to hopefully stand up to 35" super swampers which I hope the ten bolt front will be able to survive