1973 gas cap problem

[Number21]

Some dirt bag stole my gas cap for my '73 K20. Looking at various parts store websites I can see there are two caps for my truck, with or without "evaporative emissions".

I've tried both caps, neither fit. They are both too small to fit in the hole. My filler neck measures about 2" in diameter.

Anybody know what to do? Is there a third style of gas cap out there? I'm totally confused why the new caps won't fit.

[bake74]

     What model is the 73 ?

[bake74]

     Here is a list of gas caps, more than 2.  Matters is fleet side or step side.  I put in c10 for yours, but if different will need to be changed.


http://www.napaonline.com/Catalog/Result.aspx?Ntt=gas+cap&Ntk=Keyword&Nty=1&Dn=0&D=gas+cap&Dk=1&Dp=3&N=0

fixed link to show k20
     

[78 Chevyrado]

I got beaten to it. 

[Number21]

The truck is a K20 fleetside long bed.

[78 Chevyrado]

what Brand/PN# caps did you try?   I seem to remember, for my 78 C20 (No Emissions) none of the ones on the shelf worked and I had to special order one.  IIRC is was Stant Brand.

[Number21]

I tried a Murray #6049 and #6800 caps. Both LOOK right for the truck but just don't fit. I also have a Fram cap that I ordered from   that doesn't fit either.

[bake74]

    Try this site that 78 Chevyrado suggested.

http://www.stant.com/Parts-Locator/

look under gas cap and testers.

[Number21]

    Try this site that 78 Chevyrado suggested.

http://www.stant.com/Parts-Locator/

look under gas cap and testers.

That website shows I need a Stant 10649, but on amazon.com the picture for that part shows this:


The lower part that says 1 3/8", is more like 2" on my truck.

[bake74]

    I wonder if someone changed out the filler tube/metal piece that the gas cap goes on.

[Number21]

    I wonder if someone changed out the filler tube/metal piece that the gas cap goes on.

That's what I was starting to think, the cap that I had wasn't original either. Do they sell generic 2" gas caps?

Any idea what I can plug the hole with temporarily until I figure this out?

[Donut]

Go pull the filler nozzle and take it with you to the parts store.  If they have it in their hand it's easier to match up.  (on my old truck I had to do this a lot)

It's almost 40 years old, for all you know your trying to match a gas cap to an old Rambler.

[Number21]

Go pull the filler nozzle and take it with you to the parts store.  If they have it in their hand it's easier to match up.  (on my old truck I had to do this a lot)

It's almost 40 years old, for all you know your trying to match a gas cap to an old Rambler.

That's a good point, I think I can make it down to Napa without a cap. I already drove a few miles unknowingly. I would take the filler pipe off but the rubber hose it goes into is hard as a rock and I'd need to replace that too, I really don't want to have to drop the tank to get a new cap. 

[Irish_Alley]

did your old one look like that stant 10649 or close to it?

[Number21]

did your old one look like that stant 10649 or close to it?

No, my old cap was an aftermarket one that didn't look like the stocker. More evidence that my filler neck isn't original. I might take this opportunity to replace both the filler neck and the rubber hose, they're not too much money from long motor.