Our valvebody was certainly in need of upgrades. The valvebody is an automatic transmission’s control center. It contains the small internal valves that appropriately route pressurized fluid for proper operation during a particular driving condition or selected operating range. GearStar completely reconditions the Turbo 400’s original unit and recalibrates its internal settings. It begins with a TransGo shift kit, and modifies the valving combinations and calibrations as well as feed hole sizing accordingly to arrive at the proprietary specification it feels is best for the particular application.