Good question. Im assuming you have a turbo shaft with bushing in the stator support now. If that is the case I would just buy a PG shaft and go. As far as where to put the bushing in a turbo shaft application, most are in the stator support. When running a turbo shaft without a feed hole the bushing is removed from the stator support and moved to the converter. This is the proper way to do it, but some just take it out and let the converter turbin "float" on the input shaft under the thought it will center its self once the converter spins. There is some truth to that belief. As far as the drum goes a stock piston will take 7 clutches and steels when using .060 thick parts. So machining of the piston is not needed. Make sure your sun gear flange is smooth as you will have a clutch against it in this stack up configuration. A TSI 4340 shaft is $99. Plus shipping to your door.