It's done!
I swapped upper and lower control arms, steering box (I already had a leaky early 70s power steering box), tie rod ends, center link etc. and the booster, master cylinder and proportioning valve from the 73. The master cylinder and calipers were used for cores for reman. units:
I had to drill two more holes for the booster bracket so it would bolt up with four bolts. I cut the original brake rod end off after a careful measurement and welded it to the new rod making it 1 and 7/8 inches longer. I'm going to relocate the hole on the brake pedal arm because like a previous poster said the pedal goes almost to the floor. It stops on a dime though.
I replaced all of the control arm bushings and ball joints, but all the tie rod ends, center link etc were in great shape. The donor truck only had 77,000 miles on it and had been well maintained. I didn't even have to replace the wheel bearings. I had to drill one hole for the idler arm. The other hole lined up with an existing hole in the frame. The only glitch I had was that the splines on the new steering box did not line up with those on the existing rag joint. I bought a steering coupler kit from the help isle at Auto Zone and used half of the coupler off the 73 to match the splines.
All and all it was pretty straight forward. The biggest pain was bending new brake lines. I replaced them all since they were 45 years old. I made a bracket and located the proportioning valve on the inside of the frame rail a little to the rear of the firewall.
I finished at 2:30 am Sunday morning and after a short test ride, I drove it 95 miles home. I'll get an alignment done tomorrow, but on the ride home it drove straight as an arrow even though I know the toe in is way off. The difference in the drive, ride and stopping is amazing.