This is an early front bearing retainer for the Chevy 5 speed NV4500 transmission. This is for the transmission that was usually used up to 1995 with the external throwout bearing. You can identify this transmission in a Chevy by the cast "C-16812" or "C-18157". This transmission has an iron case with an aluminum top cover! This transmission usually comes in the 1990-95 Chevy 3/4 ton or 1 ton gas and diesel trucks.