I honestly have no idea. they may have some upgraded internals. I understand the torque converter is stronger on the turbos. That might have something to do with it. But the model plates all say the same ID code for the transmission. Doesn't matter if it's a turbo or not.

Hey Paul. I was reading the 85 Z31 brochure that I posted at 88hybrid and came across a statement that I thought was strange. The brochure says that the 85 NA used a different automatic transmission than the 85 turbo. Your web site said that "all automatic Z31s used the 4N71B transmission".

Is the confusion that both auto trannies that Nissan mentioned are the same tranny but set up different?