Larger Fuel Tank?

[CHLNGR]

Does anyone know of a lerger fuel tank available for Challenger?
I'd like to increase my range. With a 440 etc, I get something less than 180 miles per tank. Living in Sacramento, I'd like to be able to drive to San Francisco and back, or Tahoe and back, on a single tank of gas.
I am looking at options to increase my mileage, but what I can afford of these are incremental things. Adding 4 or 5 more gallons will make the car a lot more pleasant to drive.
Oh, and in spite of what they report in the news, half decent, premium gas in the Sacramento Valley is $5-6 a gallon.

 

[Xcudame]

2.73 gears will help on I-80. A Thermoquad carb with the altitude compensation system will help out in the change in altitude from Sacramento to Tahoe and increase milage. Or better yet, electronic fuel injection.

 

[JDMopar]

Unless you get a custom tank built, there are really no other choices than stock. I looked up Challenger tanks from a few suppliers and they are all 18 Gallon tanks, just like stock.