I have been planing a build on a Pontiac Torpedo (though I am in no position to build it just yet). One of the modifications I would like to do is to put the transaxle from a first generation Tempest in the back. This would improve weight distribution. As I would have to shorten the axles I figure I could put a pair of universal joints on it providing fully independent suspension, as in the '65 Corvair. Thing is, the manual transmissions on Tempests where only 3 or 4 speeds, which I do not think is enough. An overdrive kit could double this. I am not entirely sure if the gearbox and axle segments can be separated without screwing up the suspension mounts. Thus I think it might be necessary to put the overdrive unit between the engine and the transaxle. Would this create any problems?