Is the center pivot more separated than on the original hub of the c50? You could really get away with bushings on a center pivot.
I dont think the pinion shaft is going to like that side load either. That is fairly easy to add a support bearing to. As for the #60 chain im not sure on that. With all that gear reduction your going to have a boat load of torque.
What rear end are you useing?
The C50 hub has had the king pin ears cut off it and bolts directly to a heavy steel plate which has a pair of trailer hubs and axle stubs welded to it which allows the right to left movement. My main concern is the C50 spindle bending when the loader actually gets put to work. I plan on finishing the loader first and if I need to rebuild the center pivot will do it later.
When I started the project 15 years ago I was pitching horse poop by hand and was desperate for a loader. I have since bought a nice cabbed tractor, this project has since sat for ten years till my grandson got interested last winter hence a push to finish it up.
As for the pump and side pull, I would rather drink a gallon of snot than change it at this point. (-: In the layouts defense I work on cars/light trucks for a living, power steering pumps run for years with only a small bushing or bearing for support. This pump is located in the same position and runs by the same belt/tensioner as the AC compressor did. It's bearing was also reletvly small.
The rear ends are what I call 14 bolt Chevies. Full floating, narrowed. A substantial pinion bearing to take the side load of the 60 chain yet I am concerned. One thing I never considered was the front pinion bearing is set in a flange which bolts to the housing with about 6 bolts. Worry that flange might not hold up well.
Enough things to worry about we may just name it The Glass Slipper. For now it's running and so plan on playing with it and see what happens. Had considered mounting a front snow blower with its own engine thinking would be less stress on the tractor but as of now looks like a loader tractor it will be.