You’ll hear some convincing arguments about how the selective (conical) plastic thrust spacer is used to adjust the stack height on the GM 298mm torque converter. You also will hear some convincing arguments about how this same selective thrust spacer is used to adjust the clutch-release clearance on the GM 298mm converter. The truth is that both statements are correct. The selective (conical) plastic thrust spacer may be used to adjust both the stack height and clutch-release clearance on this converter. What is important is to be aware that changing the adjustment of one also changes the other. As long as you know the proper parameters and parameter limits of both measurements, you can adjust both successfully.