the late 70s 360 4bbl motors and mabey even the 2bbl motors in cars had 5 clutch front drums with non LU trannys. They were called A-999s. They were a heavy duty 904 non-lu. Later LU 904s from trucks in the early 80s and later had 5 clutch front drums and low 1st and 2nd gears. The low ratio gears are the toughest stock gear sets also, 4 pinions and steel cages. I know there is some way to put these drums in a non-lu 904 but I don't remember exactly what needs to be done.