my 72 had a hand switch under the driver seat, and when you switched tanks it also switched the gas gauge to the appropriate tank. so it was all contained in the same switch. this was not a production setup, it had been put in to allow the PO to haul his horse trailer lng distances without having to stop for fuel. It held 100 gallons of gasoline, 30 gallon stock and 2 35 gallon auxillary tanks. It got about 12 miles to the gallon so I was able to go 1200 miles on the highway between fillups. It was really nice but it was a depressing half hour when you filed it all the way up and this was back when gas was cheap ($1.50). 300 POSTS, OH YEAH!!!
