Need help on orig. 68 std Gas Cap

[68camaroz28]

I do not have the orig. gas cap and have no idea where it is but I did compare one NOS cap to what I believe to be a Nova gas cap. Notice in the pics the Nova cap (kinda of a white) has a much wider piece that is used to open/close and the underside has the screws with a plate but the NOS has no plate. On the Nova cap the center part of the underside is riveted to the plate and is held in place by the two screws going to the exterior handle where the NOS center part is riveted to the large round sheet-metal piece. By the way, that rivet process causes the large round sheet-metal plate to be warped. Other words, it does not lay flat whereas the Nova cap does.
Can anyone confirm what their orig. gas cap handle width is? The what I believe to be a Nova cap is approximately .670" wide and was wondering if an orig. 68 gas cap had the same handle. Also would greatly appreciate a picture/info of what the orig. is like underneath of the part that goes in the filler neck. Is it similar to the one with the screws/plate? Again, pictures of an original would be greatly appreciated. I completed some searches and found many posts concerning RS caps and 69 caps but not std..

[1968 Z28]

Chick....here ya go....   BTW, the width at the base is 1/2" and it tapers to 7/32" at the top.  And, the large sheet metal cover is warped and there are no screws anywhere.  The large metal cover is directly riveted to the outside handle.

    

Is this what you need?  If not will try harder...let me know.

[68camaroz28]

You did just fine Jerry! Now I know what to look for. Wonder what that white cap came off of or maybe that is a later service replacement for Nova??? Now I gotta find an orig. for the car...... Thank You!

[68Zproject]

I just double checked my cap and it looks just like Jerry's.  MY car had one of those locking gas caps on it which fit so poorly it fell off.  I bought a repro std cap and it fell off.  I finally found an NOS one and it fit great.  But I better paint it someday or it's going to rust as it's still primed.

[william]

GM #3910043; listed for $17 back in '93.

[68camaroz28]

GM #3910043; listed for $17 back in '93.

Yep, got three of them rascals and they all have screws instead of rivets and purchased in the late 80's I believe.
Now how can I change that screw to a proper looking rivet

[Petes L48]

Must be a drive rivet, similar to the types shown on page 156 of the AMK catalog.  Maybe a little JB weld down the hole ahead of the rivet? Seems you'd need a special tool or mallet to keep from smashing the head.   

[1968 Z28]

Chick....just now looking at the filler tube seal on the cap, is that a rubber gasket with a thin metal support underneath?  My original does not have any rubber on the seal area....it is all metal with a raised ring that seats on the filler tube.

[68camaroz28]

Chick....just now looking at the filler tube seal on the cap, is that a rubber gasket with a thin metal support underneath?  My original does not have any rubber on the seal area....it is all metal with a raised ring that seats on the filler tube.
[/quote

Chick....just now looking at the filler tube seal on the cap, is that a rubber gasket with a thin metal support underneath?  My original does not have any rubber on the seal area....it is all metal with a raised ring that seats on the filler tube.

Yes Jerry, those service replacements have a very thin rubber gasket on top of a thin metal support. From your picture I thought that was similar. Will just be on the hunt for a nice original cap!

Good info Pete and may check into that just to help change over one of the two already painted.

[68Zproject]

Chick....just now looking at the filler tube seal on the cap, is that a rubber gasket with a thin metal support underneath?  My original does not have any rubber on the seal area....it is all metal with a raised ring that seats on the filler tube.

I would guess that that might have disappeared after 43 years.  Mine looks exactly like yours but does have a rubber gasket on it. Other than that it looks identical, has the rivets etc.  Most importantly it fits which the repros didn't.

[1968 Z28]

Chick....just now looking at the filler tube seal on the cap, is that a rubber gasket with a thin metal support underneath?  My original does not have any rubber on the seal area....it is all metal with a raised ring that seats on the filler tube.

OK guys...here's the facts.  Old age is creeping up on (more likely has caught up with) me.   When I made this post I was going by memory,  I was at my sons house and far away from the cap.  Now that I am home again, I thought I had better take another look at my cap.... well guess what...my memory failed me big time.   There is a raised ring on the metal area but it is topped by a rubber washer seal.  I had taken the rubber washer off to look at the metal underneath and forgot to put it back.  So, If you do run across one without the rubber washer seal, I would say that it probably fell off or was removed and was never replaced.

Sorry for the false alarm...but at least now, I know for sure not to depend solely on my memory...

[jvb6648]

I've got an extra cap. I'd have to find it and see if it has the rivets. No luck, it has the screws. Maybe I'll use that one and put the original in a safe spot.