Greg, GE combos went from the 4 vane drum to the 6 vane drum when they changed from the machine with the tranny to the machine with the variable sheave pulley system as a speed changer in the late mid 50s. I believe it is safe to say that if it has a squared corner cabinet, it has a 6 vane drum. The combo with the tranny extracted between water changes instead of just after the last rinse.