I just got a setup from CFV for a belt drive alternator. I’ll mock it up here how it works and send pics. The kit is well worth it but you have to get the CFV pulleys for spacing. I went with a V-belt because I enclosed the water pump impeller (it’s really more of a fan from the factory, whips more coolant than it moves) on a 6 vane pump from the rear and the front, and the 18-3/4 under-drive will help keep it out of cavitation. The more efficient you can make it, the less rpm it needs to do work.