This is a propeller shaft seal that fits all 40 and 41-50 1/2 ton pickups. (1 inch inside diameter 1.690 inch outside diameter). For 1940 1941 1942 1944 1945 1946 1947 1948 1949 1950 Chevrolet Trucks

This is a drive shaft seal it fits all. 1/2 ton pickups, 3/4 and 1 ton truck. For 1937 1938 1939 Chevrolet Trucks

This is a propeller shaft seal (1 inch inside diameter 1.690 inch outside diameter). For 1937 1938 1939 1940 1941 1942 1944 1945 1946 1947 1948 1949 1950 Chevrolet Cars