'64 Buffalo,
The 11001-01 selectro are the ones. They are internal but will have a knob that goes on and sticks out about 2 inches. The 4x4 brake parts are interchangable between suburban and pick up truck. The 1/2 ton models are 2"x11" drums front and rear. Most part stores don't list the suburbans. My local independent parts store has always been able to get the brake parts.The parking brake cables I got from inline tube in Michigan. Had to send them the old ones to copy.