Gas cap "S" stamp question

[Rick T.]

I am positive I have the original gas cap for my 72 Corvette but the "S" stamp is different when compared to NOS being sold from Rowleys or on e-bay. Here are 3 pictures of my gas cap and 1 pic of one being advertised on e-bay as NOS. The stamp on my cap looks like 2 concentric circles with a "sm" in the center. The left hand side of the letter s, and the right hand side of the letter m kind of follow the curve of the surrounding circle. The NOS ones are priced as high as $130 but the stamp is just a big letter S.

Is mine wrong or are the NOS ones being advertised a later production with a new version of the logo? Mine definitely looks like it's 44 years old. I have a different vented cap that I use while driving and am just saving the the old original one. I have not had my car Flight Judged but am planning on it. If my cap is more original to a December 72 build date I would use it even though it's not as shiny as those NOS ones. Maybe they will give me points for it's petina.

Rick

[Patrick H.]

Re: Gas cap "S" stamp question

Did you check the Judging Guide to see if the answer might be there?
I would suggest the middle of page 44.

Note that NOS - at least in 2016 - rarely means that a part is the exact same as what was installed on a 1972 over forty years ago. It usually means NORS, i.e. new old replacement stock, and is a later service part that fits. That would be the case for these caps.

Patrick

[Joe L.]

Re: Gas cap "S" stamp question

I am positive I have the original gas cap for my 72 Corvette but the "S" stamp is different when compared to NOS being sold from Rowleys or on e-bay. Here are 3 pictures of my gas cap and 1 pic of one being advertised on e-bay as NOS. The stamp on my cap looks like 2 concentric circles with a "sm" in the center. The left hand side of the letter s, and the right hand side of the letter m kind of follow the curve of the surrounding circle. The NOS ones are priced as high as $130 but the stamp is just a big letter S.

Is mine wrong or are the NOS ones being advertised a later production with a new version of the logo? Mine definitely looks like it's 44 years old. I have a different vented cap that I use while driving and am just saving the the old original one. I have not had my car Flight Judged but am planning on it. If my cap is more original to a December 72 build date I would use it even though it's not as shiny as those NOS ones. Maybe they will give me points for it's petina.

Rick

Rick------

Your cap is original and is a GM #3994339. The eBay cap is also a GM #3994339 but is a later-manufactured piece. It differs in minor ways from the original, including the manufacturer's logo. You don't need to pay Big $$$ for one of these. The 3994339 is still available from GM for $60.08 GM list (much lower through discount GM dealers). You can also buy the EXACT same cap manufactured by Stant, the firm that manufactures them from GM, from sources like Rock Auto and many others for about 15 bucks. The Stant part number is 10852.

[Rick T.]

Re: Gas cap "S" stamp question

Thanks for the information Patrick and Joe. I checked my judging guide and don't know why I didn't see that description before. I realized that what I thought were 2 concentric circles are actually 1 circle and the letter "C" with the "sm" inside. I wish the guide had a picture instead of just the description that says, "...1972 units....have the logo SMC, for Stant Manufacturing Company, in circular stylized script..."

Normally the advice I receive from you guys makes me spend more money......this is a totally foreign experience for me. It feels weird, so maybe you should send me a bill for your services.

Thanks again.

Rick

[Terry M.]

Re: Gas cap "S" stamp question

Thanks for the information Patrick and Joe. I checked my judging guide and don't know why I didn't see that description before. I realized that what I thought were 2 concentric circles are actually 1 circle and the letter "C" with the "sm" inside. I wish the guide had a picture instead of just the description that says, "...1972 units....have the logo SMC, for Stant Manufacturing Company, in circular stylized script..."

Normally the advice I receive from you guys makes me spend more money......this is a totally foreign experience for me. It feels weird, so maybe you should send me a bill for your services.

Thanks again.

Rick

Be careful what you ask for; you just might get it.

[Peter L.]