I wanted to convert my Daytona to manual steering to save weight and a little power. Finding a rebuilt manual rack was no problem. I got mine off of eBay for $50 shipped. They come up from time to time. You can even get a rebuilt one from Napa or the like, but for significantly more money.
The problem is, the manual rack uses a unique coupler (different from the power racks). And, the coupler is not available new from Mopar (or anywhere else). I searched the boneyards for a used one (even through an on-line search). And came up with nothing. So, I did a little research into our manual coupler. It turns out, the rack spline is common with the Pinto/Mustang II manual rack (9/16" OD x 26 splines). And, there are a ton of aftermarket, steel and aluminum couplers available that fit that spline. But, the upper portion of the u-joint is obviously different. As luck would have it, the u-joint and needle bearings just happen to be the same as stock in several of the aftermarket couplers. So, it's simply a matter of carefully dis-assembling both the Chrysler and aftermarket coupler U-joints, and then putting the aftermarket lower end on the Chrysler upper end.
The coupler I bought was made by Borgesson, but there are others. The Borgesson uses the same Torrington needle bearing (P/N 59500) and "T" as the stock Chrysler part. I think they must be standard Torrington parts. The Borgesson coupler does not have the "D" feature on the spline that the rack has. But, that won't keep the coupler from going onto the rack. It will, however, make it harder to center your steering. You will have to carefully find the center of the rack, and center the steering wheel before slipping the coupler onto the rack. The "D" takes care of that in the stock coupler. The set-screw on the Borgesson coupler fits perfectly into the groove previously used for the roll pin.
The bearings for the Chrysler coupler are staked in place. Which makes them difficult to remove. Since I had no need for the bottom yoke when I was done, I disassembled the original Chrysler u-joint by simply cutting the bottom yoke loops. That left the "T" and bearings attached to the original upper. The Borgesson coupler also was staked together (you can see the stake divets in the pictures). But, in this case, I needed the lower yoke to be re-useable. So, I carefully ground the stake divets with my dremel tool. Once they were ground down far enoguh, I pushed out the bearings with a similarly sized socket and hammer. A press would be better, but I didn't have access to one at the time. There are also aftermarket couplers that hold the bearings in place with a small screw. Which would be much easier to use for this conversion. After I had the lower yoke free, I put the Borgesson lower onto the Chrysler upper and staked it back together. Make sure to take all of the side play out of the bearings. If you don't, it will show up as steering wheel slop.
That's basically it. I didn't take enough pictures of the conversion. It went too fast. I had the new coupler together and on the car in less than an hour. I do have some pics of the completed installation that I'll dig up and post later.