After being told I might have better luck in here I have posted in this section now.

I have "kind of" started a build on a fl350 odyssey. The issue with the odysseys is that the gear box was blown up when I bought it. I now own a 1000cc sled motor that I am planning on running in this. I already know that I will have to do some reworking of the frame to get the engine to fit.
My major issue is how to get the rear drive shafts connected. I do still have the original splined shaft that connects the two but there are so many different surface heights that I don't think it will be strong enough once it is machined down. Also I could use a few ideas on how to hold the shaft in place but still allow it to be removable in case of a break that could happen.

 Basically all I need to mount on this shaft is the rear sprocket because I have the whole front end of the sled which already has the brakes and clutch mounted on it (planning on keeping this as one unit and fabbing some type of mounts to mount it in the frame).

The second issue is could I machine down the shaft that the "Pucks" for driving the track into a round shaft and mount a "front" sprocket on that shaft.

I am sure I will have plenty more questions once and if I ever get started on this project but TIA on any tips or ideas that you may have.