Gas cap numbers?

[RICH MUISE]

Does anyone have gas cap aftermarket numbers for the vented and non-vented requirements? I found an ebay seller with lots of nos caps, so I need numbers for aftermarket companies like Robertshaw, Stant, etc.
Specifically I need to know if a Robertshaw RG-31 is the right non vented cap.

[Wirenut]

I'm glad to see your inquiry. I have bought 3 gas caps for mine and still do not have a good fit. I hope someone can help. Thanks for posting Rich.

[canadian_ranchero]

the best i can come up with is a gates number 31631.the gates catalogue says the gas caps fits 53 to 63 ford full size sedans.they say it is 2 7/8 wide overall and 1 1/8 high overall and where it fits the filler neck it is 1 1/2 wide.they call it a deep cam; space between gasket and ears that engage filler neck are longer.the shallow cams are about 13/16 high overall.hope this helps

[RICH MUISE]

Interesting on the shallow cam statement. I wondered exactly that about my aftermarket gas tank. My locking gas cap, which leaks a little, pushes in until two tabs snap in place. there is no turning to engage the cam action. As hard as it is to push in, when it does engage both tabs, I can still rock the cap back and forth a little. A deeper lip on the filler neck would seem to solve that issue, assuming I had the strenth to engage it.

This is a link to the ebay seller on the nos aftermarket caps. I ordered one yesterday, so I'll know in a week or so if it at least fits. I did send him an email asking if it was a non vented or vented cap, but so far haven't got a response. From the pics. I'm 95% sure it's non vented.
http://www.ebay.com/itm/262376522157

[hiball3985]

That looks like the standard non-vented cap to me..

[clusterbuster]

I too need a new gas cap, as two of the ones I bought had a loose fit, and I had to return them. I searched the Gates Automotive catalog on line and there is no 31631 listed. The highest gas cap part number is 31625.

[RICH MUISE]

Out of curiousity, Cluster, original tank or aftermarket?
I'll post how the one I ordered fits after I get it.

[clusterbuster]

It's an aftermarket tank Rich. The neck is the same as the original, as my old locking cap off the original tank fits the same.

[Wirenut]

It does require a deep cap inside piece. The catalogs show the caps to fit a range of years in luring the 57 but do not. My tank is a new tank but takes the original cap. As mentioned earlier I have bought three that the various catalogs show to fit but no luck yet. Hopefully an actual cap and number may come out of this interaction.

[canadian_ranchero]

I too need a new gas cap, as two of the ones I bought had a loose fit, and I had to return them. I searched the Gates Automotive catalog on line and there is no 31631 listed. The highest gas cap part number is 31625.

the number is from a 1975 catalog.it was not listed in my 1986 catalog,but was in the 1996 gates jobber data guide.you will have to check with gates,it may be discontinued

[clusterbuster]

I ordered one from Ebay today as well Rich. Venting should be okay or he has a lot of mis-information for all the Ford vehicles that it is supposed to fit. Thanks for the tip.

[RICH MUISE]

Got it today. It's a really nice tight fit on my old gas tank. I do not believe it is vented, but to be 100% sure, when I have a minute, I'll throw some solvent in the tank and turn it upside down on the filler to see if it leaks. I've got my new tank filler all masked off for painting the car, so I won't check that fit for a while.

[Wirenut]

That's good to know Rich. I'll order one now. Thanks for posting the info.

[RICH MUISE]

I ordered one from Ebay today as well Rich. Venting should be okay or he has a lot of mis-information for all the Ford vehicles that it is supposed to fit. Thanks for the tip.

Problem is...it fits as advertised, but no specific models were noted, and we know the wagons need a vented, the passenger cars need non-vented...so yep, it fits but may not be what is needed for a specific model. With that said, the seller did say he had thousands of nos caps, so if something specific was needed, forward him the info. Tommorrow I'll try to get some liquid in my old tank in storage to see what I've got.

[djfordmanjack]

Rich, I just happend to come across a small lot of NORS caps recently and thought I'd share this for reference. Here I have a NON vented STANT G31, fits 53 to 63 Ford pssgr according to the box.
I also found another old Stant box in my pile that I used the non vented cap for my 1962 Mercury Comet and the box states also a fit for 53 to 63 Ford pssgr. #is G22
I tried the G31 on my Del Rio filler neck and will go in the bayonet, but will not tighten up and lock ( because the wagon needs a vented one).
it's incredible how nicely those cheap old NORS caps were made in USA, when compared to todays cheap aftermarket crap, which cuts your fingers as soon as you get it out of the box.