70 GMC 4wd version

[Axe]

Your build looks great, If you haven't found a drive shaft any 1/2 ton with slip yoke should work 208 or 241 tc, if you can find one longer should be around 35.00 to have shortened. On your bumpers with the body lift back just weld a piece of angle on top of your frame and relocate holes for bumper, this way you don't loose any strength if you still want to tow a trailer, the front just cut your frame horns off and move them up an inch or whatever your body lift is. I have an 85 blazer I did it with a 3 inch body lift, bumper looks stock now.
Good luck and great work can't wait to see it finished.