I put a 3/4 ton crossmember into a 1 ton truck, they were both 4x4 and the crossmember bolted right in. I believe the front of the frames are all the same height, the difference is from the cab back to the rear axle. Nothing is bolt on from 2x to 4x so you can use hangers and crossmember from whichever trucks you can find....1/2, 3/4, or 1 ton. The rear spring spacing is narrower on 1 tons though. You can reuse the front hanger on the rear springs and do a shackle flip to raise the rear.
You can get aftermarket front spring hangers and front upper shackle hanger (FUSH) from diy4x.com as well as a shackle flip.
All it takes is patients and hard work and you can accomplish anything
We currently have four 1 ton 4x4 crews and a 3/4 ton 4x4 suburban sitting at our house along with a 66 2wd pick up (same basic frame in the front as the 1/2 ton square bodies, with some differences) I am willing to help with measurements and pics if you need them.