dual tanks dealer add on

[kglowacky]

just noticed as I walled by my truck bed that the gas filler holes on both sides of my truck are different. The drivers side has a recess where the filler neck bolts to the bed and the pass side does not. I also discovered I don't have a dash switch hole for the gauge switch change in the cab. I do have a two way valve under the seat. I do have both tanks and hangers. Did they come with only one side recessed and/or did dealers add these at the dealerships upon request.

[1976gmc20]

Standard was passenger tank; driver side tank was optional.

I did have the dealer add a tank to my 1980 but they put in a factory type switch. Obviously the filler was different because by then the factory tanks had a door.

Lots of tanks got added back in those days by other than dealers, either other shops or folks did it themselves. There were saddle tank kits available for the pre-1973 models long before the square bodies were introduced. I put on several extra tanks when I worked for an RV dealer back around 1974 or so.

[kglowacky]

correction on my thread. The pass side is indented drivers not so what you say I agree with. Thanks
anyone have a beat/rusted beyond repair pass side bed that has the recess they want to sell. all I want is about 4 inches square around the recessed filler hole. mine is a 78 model no door