Good ideas to consider Dan. Wonder if an epoxy putty would work to fill in the worn splines and then a bolt to hold it in place.
Another thought, Drill a cross hole thru the yoke and the input shaft and then ream it to take a taper dowel pin. Then have a new spline welded in the drive shaft and balanced.
Now to take us back off topic. After taking the pictures. I was sliding back out from under the truck and stirred up a wasp nest under there somewhere. Our German Shepard knocked down three of them so I could stomp on them. Neither one of us got stung. His nickname is Deer Slayer. Here is a picture of him chasing a eight pointer across our pond and then a couple of boys dragging it back to the house, two days later.
Don
1967 GMC 9500 Fire Ladder Truck "The Flag Pole" In the Stovebolt Gallery 1946 2-Ton grain truck 1946 3/4-ton pickup, 1953 1-ton pickup 1957 1-ton flatbed dually, 1954 Pontiac Straight Eight Of all the things I've lost in my life, I miss my mind the most!