[dsraven]

Hang from the rafters at the approximate angle you need and then drive the truck under it. Worked for me once. If you use a come along or some sort of easily adjustable mechanism you can lower the hood slowly or use the floor jack under the truck to raise to the hood height. Then get a couple of bolts in the hinges and remove the mechanism. Use tape on the edges so the paint doesnt get scratched up. Worst case scenario.
If you have an engine lift you could build a structure from 2x4s that would work. Like a lot of guys have built for lifting the cabs off. Then suspend the hood from that.
Put a blanket on the cowl area and fenders, tape edges. Pick up hood from front with engine hoist and guide the rear of hood manually. Place hood on hinges and allow lift to hold hood while you get the bolts in.
Somebody on the hotrodders site built a mechanism to do this, it had hinge points and was pretty cool. Cant find it now though.a few years back.