Transmission General Information:
All 1017 and 1018 Velvet Drive Reduction units use a 5 inch coupling. You can easily replace a 1017 with a 1018 but it is 7/8 of an inch longer. Make sure you can move your propeller shaft coupling back 7/8 of an inch to be able to use the much heavier duty 1018 series transmission.
The 1.91:1 and 1.88:1 Transmissions reverse the rotation output from the input. An automotive rotation engine with a 1.91:1 or a 1.88:1 will use a RH propeller. This is the only Velvet Drive 1017 or 1018 series that does this!
Velvet Drive 5000 Series can use a LH or RH propeller, but can only be used on an automotive rotation engine.
Hurth and ZF Series can use a LH or RH propeller, but can only be used on an automotive rotation engine.