PK4412004 is a non-lockup, long extension housing, A727 transmission that was originally equipped in 1987 1/2 ton trucks with 115"--131" wheelbase, and 3/4--1 ton trucks with 131" wheelbase, with 318-4bbl and a low stall converter.
PK4412004 was also originally equipped in 1987 1/2--1 ton truck all 360 applications with a high stall converter.