Classic Industries Stainless Steel Mopar Fuel System

We’ve introduced our new project car, the Millennial Duster in these pages already. To recap, it’s a 1974 base 318 V8 car. The goal is to keep the classic lines and looks of the car while upgrading the drivetrain, suspension and interior to the standards that Gen X and Millennials have come to expect from a car. You know, brakes that work, fuel injection on an engine that always starts and runs strong and provides good gas mileage, that sort of thing.

We’re almost ready to build the engine; it’s a 360 small block stroker that will have 408 cubic inches of displacement when we’re done with it. We’re shooting for 500+ horsepower from the car. But, while we’re working on the engine, we need to occasionally move the car around the shop or park it out on the street. This need to start the old girl revealed a fueling issue that is partly a result of trying to use a 1974 model car in 2016.

You see, back in the day gasoline was gasoline and alcohol was alcohol. One was put into your car’s fuel tank and the other was put into your martini. OK, fine, some race cars ran on alcohol even back in the day, but you get what we mean. But, for various reasons related to a push for renewable fuel and some smart lobbying from farm groups, the fuel you buy at the corner gas station now has alcohol in it. Up to 10% of the gasoline you buy can be plant based alcohol instead of fossil fuel based. And herein lays the problem.

Alcohol and gasoline shouldn’t coexist; it’s as unnatural as cats and dogs living together. Literally it’s like oil and water being asked to mix. But put modern chemical science into the mix and viola, you have gasoline with up to 10% ethanol content and everything is fine. No, wait, it’s not. Because where’s there’s alcohol there’s water, and we’re not talking scotch and water here. We’re talking water in your fuel system.

As much as gasoline and alcohol hate each other, alcohol and water love each other just as much. That’s why Jack Daniel’s doesn’t settle out to the bottom of your glass of Coke when you mix them. Alcohol (ethanol) molecules are hygroscopic, which means ethanol attracts and absorbs water, including the condensation that forms in your fuel tank. Moisture from the air bonds with alcohol in the gasoline and now you have a highly corrosive mixture stored in your tank, coursing through your lines, your fuel pump, etc.

Since back in the day all gas stations sold fuel that would satisfy any teetotaler it was no big deal. Our Duster’s fuel tank was made from galvanized metal as was typical for the time. Galvanized metal is steel that is coated with a more corrosion resistant metal, typically zinc. Over time, as in the 40+ years that our Duster has been around, the coating itself corrodes away and the underlying steel is exposed. If you have an older car, it’s not a matter of “if” your fuel system is going to corrode and cause problems, it’s a matter of “when” it will corrode.

In our case, the failure was catastrophic. One day the car just wouldn’t fire up. There was no fuel making it to the carb. We threw a new fuel pump on the car to no avail. We ended up with a one gallon gas can zip tied to the inner fender and hose feeding the fuel pump, just so that we could move the car around when needed. Obviously, this is not a long term solution.

The long term solution is stainless steel. Modern vehicles have polymer plastic fuel tanks that cannot corrode. But for a lot of reasons that’s not a good option for classic cars. Stainless steel is by its nature corrosion proof. So if you have a fuel tank and fuel lines that are stainless steel, you don’t have to worry about the ethanol content of your fuel.

Enter Classic Industries. If you own a classic Mopar you should have a copy of Classic Industries inch thick Mopar catalog on your nightstand (see the sidebar about them accompanying this story). We contacted them and ordered up a stainless steel replacement tank, fuel line and the other parts noted below for our 1974 A-body.

Part#Part Description
FT6005C Fuel Tank, “Stainless Steel”
MF449 Fuel Tank Straps, “Stainless Steel”
MF238 Fuel Tank Insulator Pad
MM8271 Fuel Tank Mounting Studs
MF296 Fuel Filler Neck Grommet
MF368 Fuel Tank Cap, “Primer”
MF518B Front to Rear Fuel Line, “Stainless Steel”
MF256 Fuel Tank Sending Unit