Hanlon motorsports or your local transmission supply house. We have a place here called Lester's Gears...just about everything that has to do with transmissions (manual and automatic) in stock.
sorry been away working on it for a while because after the problem started it was after a hugh burn out and something wasent right i thought it was the rear end so i replaced the pose ring and pinion iner and outer bearings so that elimitated that i took the drive shaft to a aamco they spun it and told me it was balencend and fine all moter and trans mounts are good and new bearnings in front also perfect alinment i told all that to guy at aamco and he said it a possable cause would be bent input shaft but i would love some other ideas and how to check them
thanks drew