1963 NASCAR International Rule Book Specifications NASCAR Grand National Championship Circuit Section 20-21 -- Fuel and Gas Tanks

a. Gasoline only as fuel. NASCAR reserves the right to have all cars use one brand of gasoline.

b. Fuel tank maximum 22 gallons including filler spout. Tanks must be strapped lengthwise and crosswise, and must remain in original position. One 1-inch maximum vent to outside of body at left rear light. Left hand fill or center fill only. Production size filler necks only not to exceed 2 1/4 inches outside diameter. No rubber connections between filler neck and gas tank unless they are enclosed in metal. Plywood on top and bottom of tank recommended. Pick up in fuel tank may be moved to right side.

All fuel tanks must have a removable drain plug; otherwise tank will have to be removed for inspection.

Firewall of steel not less than 20 gauge thickness must go between trunk and driver.

c. Electric fuel pumps not permitted.

d. No water cooling permitted on fuel pump.

e. No additional lines may be used on fuel systems.

f. Fuel lines from tank to carburetor may be relocated to prevent vapor lock, but must remain under floor of car. Line may be replaced with neoprene hose not to exceed 1/2 inch I.D.

g. No pressure system allowed.