I WAS playing with the idea. I have since sold the 350's I was going to modify. What I found out.
The 350 tranny output shaft has the same spline pattern as the 350 hub (which incidentally is the same as the FL250 rear hub, and the 400ex rear hub) I was going to get a set of hubs and machine them to the same diameter as the inner CV joint of a 1995 geo metro passenger side drive shaft, and weld that together. I was going to use the bearing carrier and hub from the metro as the new bearing carrier and hub for the 350.
The rear suspension was going to be constructed very similar to the drakart rear and new trailing arms , and shock mounts were going to be made. I had planned on using fox air shocks for the rear suspension.