Thanks ZohmBii.
Next up, found a nice dry spot in the shed, and started dismanteling the Pickup.
Took the bed and wheels off:
Took the axle out:
Front suspension disassembled:
everything against the wall:
Cleaned off the new 5-lug rear axle:
cleaned off the frame a bit, put some wheels on the axle and held it in place to have a look at it:

seems like it could work
Trying to not die while disassembling the front suspension from the 5-lug front axle

I found out that the spring from a 1973 c/10 are a little longer and have more pre tension than the sprins from a 1792 c/20. So without any weight on the axle it was a little sketchy to get it all apart.
But, didn't die, got it apart. Win for me
Thats it again for now, fun stuff starts tomorrow!