This is a Reproduction Of Original. Seals The Upper Filler Neck At Body The Chevy gas tank filler neck O-ring encounters much stress during the daily duty of your 1961, 1962, and 1963 Full Size Chevy. Leaks stemming from your fuel system are never good, and can often be quite damaging. A possible leak source is from the filler neck tube because it suffers tremendously from vibration and flex. This immense stress will often result in deterioration, requiring you to replace the filler neck. When this replacement comes, you will also require new O-rings. This rubber O-ring is located on the inside of the gas tank inlet lip. Simply remove the old O-ring and discard, wipe the O-ring seat clean with a rag. Remove the large hose clamp, disconnect the hose at both ends, lubricate the new seal and place it in its groove. With a bit of time and Ecklers know-how, you will be back on the road. Invest in a new gas tank filler neck O-ring for your 1961, 1962, and 1963 classic Chevy today. Available at Eckler's Late Great Chevy today. .