Here is my first Moon tank. it was an easy to mount the gas tank fowared of the engine and not have fuel lines in the plane of the clutch/flywheel. Didn't need a lot of gas to go 1/4 mile so a 5 gallon than with 2 1/2 gallons of fuel and the rest with pumped up air pressure was fine.
i like moon tanks weather it for looks or function. ive heard of people using them for a battery box.
In a time when they were trying to transfer weight to the rear for traction, It seems strange they would mount it on the front bumper.
The big reason moon tanks were mounted in front is because alot of them were used with fuel injection and the pump for injection does not like to pull fuel along way. Gregg
This is the #1 answer I could think of....I ran hilburn set up once...built a box with holly floats to feed pump......80s street car
I have a small one on the front of my truck, its my overflow tank (puke tank) I know thats not what they were origionally for. Origionally for fuel.