That's the bit where I am stuck - there does not seem to be a sliding joint. From memory the type 9 box had a splined drive that the end of the propshaft went in to. The prop could slide so that as the engine moved in relation to the diff it would not go tight. You could push the end of the shaft all the way in, line up the rear of the prop with the diff and just bolt it up. The sierra seems to have a different arrangement where the splined, sliding part if half way along the prop shaft. It looks like the donut assembly is fixed ie it does not slide in and out of the output shaft but the movement is in the joint half way along the propshaft. Does that make sense?
I can't see how a 1 piece prop can work
