THM 400 Archives - Transmission Digest
GM 400, 4L80-E Case Saver Retainers

Protect case lugs from blowout with the only intermediate clutch retaining ring case saver that allows the intermediate band to be retained. Only the Sonnax case saver retainers support the intermediate clutch retaining ring, yet are thin enough to allow the intermediate band to be installed, allowing case lug protection in all applications. · Fits

Retrofitting the GM 12-Inch 350/400 Non-Lockup Converter

The GM 12-inch 350/400 non-lockup converter is still very popular with torque-converter rebuilders. The converters are needed for many vehicles from that era that are being restored, and even more are used in the construction of street rods. The high demand and limited availability for cores have been an issue with some rebuilders. The lack of cores is easy to understand when you consider it has been more than three decades since the last GM 12-inch non-lockup converter was manufactured.