Diff gear recommendations

Thanks Rob, MUCH appreciated and a driveshaft like you said, "big whoop". That was included with the "plans".
Steve, remember where they talk about the tunnel being tight and cutting ribs off the transmission to make it fit, they're talking about an early A body, which yours is not. The lockup transmission will bolt into your car. You may have to do something with the drive shaft, I'm not sure.....but big whoop, right?