I stumbled across this today, and thought I would bring it up to date with what we have done.
We ended up going with the factory power steering unit. The pressure bypass worked out good, the steering functions as well as it did when the car was new. We have a tight steering box, and everything on the front suspension has new or rebuilt parts.
Once we had the motor mounted, the very limited exhaust exit options under the car eliminated any steering rack option. Things are very congested down there between the steering, the torsion bars, the oil pan, the transmission, and (2) 2 1/4" exhaust pipes.
We used a 8.8 rear axle from a Ford Explorer. It has the disc brakes, and a 3:73 Limited slip rear gear. The Explorer axle has mounting places added to attach to the car's leaf springs. The Ford rear end is pretty narrow for the wagon, we will need wheels with a max of 3 1/3 backspacing or the tires will rub on the inner fenders. We had to buy a ujoint flange to match up with the Mopar u joint. (Sorry, I don't have the part number, or where we bought it. it was a standard Ford part though.) The car has a disc brake conversion and a GM booster and master cylinder (all new parts that all came with the car, so no info on where it came from). The brakes are awesome.
We did use the Jimmy tank and fuel pump. We had to get a return line regulator, one that dead headed would not reduce the pressure on the 97 Mopar port injection rail.
We used a Hot Wire wiring kit. It is a very nice kit and worked well. The tech was very good, they were very helpful when I did a dumb thing, and walked me through the "fix". My dumb thing was we rewired the car. It was some cheapo wiring kit that was incorrectly wired at the fuse block. Buy a good wiring kit, not the cheapest thing you can find. We ordered out car wiring kit as a 60 & 70 Mopar replacement wiring kit. The engine harness we ordered for a 57 Dodge car with the 5.9 gas motor. What we didn't realize was the original 57 Dodge had a key and a push button start (that stuff was all gone from our wagon). We wired the car with the key to crank, with ignition and accessories. The engine harness we ordered was for a key with ignition and a push button crank. When we cranked the motor with our key, we didn't have any power to the ignition, and as soon as we left off the crank, we had ignition. Once we moved the crank to a push button, the car started and ran great. It was a pretty frustrating few days before me and the tech guy found my issue. He bent over backwards as we walked through the mess I created.
We did have to cut our predestine floor pan and enlarge the trans tunnel about 2" to clear the driveshaft. We also had to drill a 2 3/8" hole for the engine wiring harness to pass through the firewall. We did remove the factory heater core assembly, we were concerned about clearance and it had to come off to install the motor. We were (and still are) concerned about the condition of the heater core. I believe the assembly would clear the motor, but if the core is bad, a different system will have to be designed. For now, the hole is covered with a piece of sheet metal. We adapted a gas pedal assembly and cable from a 97 Dodge truck to the car.
We added a counsel to house the automatic shifter that was adapted from something else, with home made linkage. The engine control computer, the relays and the fuse boxes are currently in the counsel as well, but they may be moved shortly. Seats and seat belts out of a late model Durango were installed. The goal we had was to get the car drive able by the end of last summer, then upgrades would be made this spring. We managed to accomplish our goal by the beginning of August and probably logged around 1,000 mile until it was parked in the fall. I don't have pictures of the assembled car, but i have pictures of it with the front clip off. Maybe my son will post up pictures of it as it was seen on the streets last fall. Gene