 Starting in 1973, AMC discontinued the use of the adapter ring, as it sourced a TH400 case from GM with the AMC bellhousing pattern already cast.The TH400 AMC case was used until the end of 1979 model production.The 232 I-6 used in 1970-72 Jeep DJ "Postal Jeep" was backed up by the Borg Warner T-35 3-speed automatic.