Did you lube the pilot bushing and the front of the shaft before attempting to assemble? You could start your bolts and see if they will snug the transmission into place. Just some thoughts from my own experiences.
Yes, I put a little grease on the pilot bushing using the plastic input shaft. I wanted to leave the bolt idea as a last resort.
Did you compare the new pilot bushing to the old one removed to be sure they were the same thickness? Alternative thought. Did you by chance replace the input shaft in the transmission?
Yes, I compared the pilot bushing and also test-fitted it on the trans shaft. They reused my original input shaft, so that was good. I am not an expert on the internal parts, but was told the 1st and 2nd gears were bad along with the synchro's gaskets, etc.
So, I moved the clutch fork, as I used a pry bar against a crossmember on the back of the transmission, and it made that awesome sound as it fully contacted the bell housing. I guess I just needed a little extra push!! Hard to do by hand on the ground under the truck!
Thank you, everyone, for your help. The truck has been sitting in the backyard for over a year with no end in sight until one day I found someone selling an SM318 they had in the back of their storage trailer for years. Although the tail shaft was shorter (From a car with that X frame back in the day), the rest of the parts were in great shape, and he only wanted $20 for it. My transmission rebuilt below...
