Power switch For GM Clutch Converters, 1981 to 1991 Application: 1981 to 1989 GM TH-700R4 1981 to 1991 TH-2004R, 200C and 350C Operate your vehicle as a standard type torque converter when it is more desirable than the lock-up type. The Power switch kit supplied for these transmissions only locks out the converter clutch in first through third gear. The TH700-R4 and the TH2004R will not function properly with the lock-up converter locked out in fourth gear. The Power switch kit automatically overrides the switch in fourth gear in overdrive transmissions.