Interesting. I guess I just never realized how small the individual tanks were. Thought they were each the standard size. And I never happened to experience the rocker switch failure, not that I doubt you.
As for being located outside the frame, it was proven that NBC television had mocked up those trucks and augmented the flame to produce a jarring video for tv. Then again, new ones are on the inside of the frame, so why couldn't a second one of similar size be located on the other side?
The tank on my 2014 GMC K1500 is only 24 - 25 gallons (oddly, my 1994 Chevy K1500 Blazer - think original Tahoe, but 2-door - had a 30 gallon tank). The allure of a 2nd tank, so I could lug around 50 Gallons and traverse 800 to 900 miles between fill-up calls to me
The rocker switch wasn't the problem, it was the mechanical part that switches the fuel/return/breather lines. I recall they were a problem to keep working.
The issue with running another tank on the other side is that is where the exhaust pipe runs. What you could do is put the spare on a swing-out on the bumper (like Jeeps do) (or somwhere else) and run a 2nd tank where the spare was. Its within the frame perimeter for impact safety, away from the muffler and catalytic converter heat, and not that hard to run a filler neck to it. I've thought about this but I don't have the mechanical skills to pull it off.
I hear you about tank size. My 91 Chevy pickup had a 34 gallon tank from the factory and got ~20MPG. 600 miles with reserve was nice when running around the west. Now they have 23 gallons - ******? I remember GM running an ad back then bragging about how you could run all weekend without having to find a gas station. I often did exactly that.
The main reason the TV crews "augmented" those tanks was to make sure the fire happened during the photo shoot. They didn't always start on fire, but they did all too often in the real world. Before the saddle tanks the tank was in the cab, behind the seat. Those fried a few people too.
Where they put the tanks now is pretty safe. There is room there for a bigger tank but the weight reduces MPG slightly - and that is why the smaller tanks now days. They are doing everything they can to hit those CAFE numbers - small tanks, auto stop-start, charging the battery to only 50%, direct injection, etc.
I often miss that 91 even though it was 2WD. Long range, manual trans, 8 ft box, it was a great travelling truck.
