27/50t Gears
G.O.S.S is now offering both m66 diesel 6th gear sets. Have you purchased the m66 diesel 6th gear to realize that the mating gear is discontinued? 
We now produce  the gear that was discontinued by the original manufacturer. Our heat treated gear is CNC machined and CNC precision ground.
This gear set offers a significant reduction in rpm when at hi way speeds. 
6th gear overdrive. Save on gas , reduce cruising rpm at highway speeds.