yes originally the model B and G had the same bevel gear and pinion in the transmission. But somewhere in the 21000 serial numbers. both those machines were updated to the newer bevel gear and pinion design along with different final drive gears that the HD6E had had since number 14484. So consequently the HD6B,E,G all used same transmission and final drive gears from somewhere in the mid 21000 serial numbers up to the last HD6 built in 1974 which was 25271