GT gas tank with racer flip-up gas cap

I purchased an over-sized gas tank (16 gallon) from JPS. John relocated the gas feed neck and included a quality racer style flip-up gas cap. Excellent piece.

I will soon cut a hole in the trunk for the gas cap to peak through.

John suggested I buy a black toilet plunger, cut a hole the size of the feed neck and slide it down the neck. Add a piece of clear tubing to the now rain gasket so any water that gets around the gas cap opening can drain from the catch basin to beneath the car. Low tech trick.

I had John install a 13 gallon tank in my new JPS. I notice that he had cut a circle in the fiberglass support structure right over the gas cap but didn't go thru the trunk lid, guess this to clear the cap when the trunk lid is closed. My observation is that the 13 gallon tank is higher in height than the 9 gallon standard tank to achieve the extra 4 gallon capacity. Bruce

Bruce, you are correct about the taller proportions of the larger gas tank. (I thought they held 15 or 16 gallons...) Besides having a longer range, I am looking forward to the added weight of the extra X number of gallons of gasoline over my front axle.

Yes, I have heard of the inner layer of the hood needing a hole so the gas cap will fit beneath the hood. George mentioned this with his new car.

In my case I wanted the racer gas cap exposed through the hood so we are cutting the hole through and through. John had to modify the neck by lengthening it some... I think, or maybe he re-positioned the filler neck, frankly I haven't paid attention.

I have to tell you the flip-top gas cap John sent with the tank is a very nice piece, made in England, great quality.

For the rubber piece you can use a " big truck " Mack / Freight Liner Etc. shifter boot and turn it upside down/ it already has a round hole in the center ....looks better than a plunger

Alan M

GREAT suggestion Alan!

I too swapped in an oversize gas tank in my JPS for all the same reasons. The filler neck was located on the right side near the stock tank location. Don't know if this particular tank had ever been modified before I got it. The extra tank height raised the filler cap up into the hood inner liner. Since there is nearly an inch of empty space between the hood inner liner and outer body shell in that area it is an easy thing to cut a 3 inch hole by hand through the inner liner. You only need about an extra half inch of height to clear the gas cap. Works great. Next time I'm looking at the flush aircraft style brushed aluminum caps, like some Mitsubishi cars have now.