Nice find! There are quite a bit of people who use readily available clutch kits from McLeod and other manus, that utilize a hydraulic release bearing that eliminates the use of a fork. The downside to that is maintenance, in my opinion.
I have been researching this quite a bit and to the best option I've seen used from multiple posts on multiple threads, here on this forum, was the use of a 7/8" bore master cylinder and a 7/8" bore pull type slave cylinder that used the fork and pulled it rearward.
I've seen some pull master/slave combos on ebay for around $150. The fork that was used was a typical A body fork, drilled for the pull rod where the spring usually goes into it. The slave cylinder was anchored back at the trans crossmember.
This is another thread that is going long, regarding different types of methods used.
http://www.forabodiesonly.com/mopar/showthread.php?t=111276
The reason I like the 7/8" master / 7/8" slave pull is because it's easily accessible for maintenance and replacement.
If you are looking for an easier foot than the 3 finger type pressure plates, I know that McLeod and other manus do offer a diaphragm type clutch pressure plate. I've seen some for around $150 for the 10.5 clutch. If you do use them, you are supposed to ditch the overcenter spring at the pedal. I think that spring, along with the 3 finger type diaphragm is largely to blame for the pedal stiffness, along with any poor linkage function of the Z bar, etc.
The nice thing about hydraulic is that you ditch the Z bar and it works with 3 finger or diaphragm type pressure plates. The two 3 finger clutch cars that I've driven felt stiff. The diaphragm clutch car that I drove was nice and still used a Z bar. I'd imagine using both diaphragm pressure plate and hydraulic actuation would make it feel like a newer car.
If you can't find a 5.1" Bellhousing, the 4.8" works if you have it machined out, or you can use a different front bearing housing or possibly machine it to match whatever bell you can get.
