[x-bird]

ssm-- i think i have about 60 percent of your setup visualized, and get the basic theory of it. Both yours and metal's make me think I'm missign something in my own thinking. What I had in mind was the engine/trans and sprocket all fixed to the primary framework, non floating/pivoting etc. a pair of "y" arms off the rear (they'd be more like an upside down "h" and would use the existing rear frame mount i have by adding another pair of square tube extensions with the bronze bearings at center and then sliding a 3/4 tube or rod through both arm sets. the arms would be 2 to 3 inch diameter on the straight leg portions (possibly 1 at the pivots worked up to 2 then ovalized for most of the straight length to resist the twist) and house an axle carrier hub. Universal joints on one side of the halfshafts would be attached to a stub shaft through going through some type of block/bearing mount on either side ofthe sprocket and go to the carrier bearing at the end of the arm. Range of motion would only be the arc of the arm from the rear frame pivot, it'd have the shock mounted on top and going up to a point around the outside edge of the rear seats. I don't think there would be a stiction issue caused by an arc of travel versus true vertical with a sliding halfshaft with universals on either end.