1971 Fuel Cap Restoration - Recommendation(s)

[Ray K.]

Does anyone have a recommendation on who be their "best choice" to restore an original 1971 LT1 original fuel cap?
Attached are jpegs of the top and bottom side of my original cap. Since the '71 caps are just about impossible to find and/or replace, I'd really to like have my restored. . . . . .
Thanks
Ray K #43777

[Joe L.]

Re: 1971 Fuel Cap Restoration - Recommendation(s)

Does anyone have a recommendation on who be their "best choice" to restore an original 1971 LT1 original fuel cap?
Attached are jpegs of the top and bottom side of my original cap. Since the '71 caps are just about impossible to find and/or replace, I'd really to like have my restored. . . . . .
Thanks
Ray K #43777

Ray------

While I have no personal experience on this score, I'd say that Joe Perri is probably your best bet. He advertises in the Driveline.

[Mark E.]

Re: 1971 Fuel Cap Restoration - Recommendation(s)

Joe,

A couple years ago you posted the current service part replacement is identical to the original and not very expensive. So I purchased one for my '70. It's not in front of me but it looks like the '71 in the photo sans the red caution tag.

[Sal C.]

Re: 1971 Fuel Cap Restoration - Recommendation(s)

The service replacement and the current reproduction are far from the original.

[Mark E.]

Re: 1971 Fuel Cap Restoration - Recommendation(s)

I replaced my original '70 cap with the current service replacement about three years ago. It looked identical except for condition.

Maybe '71 is different? Going by memory and the above photo, '70 and '71 look similar except for the red tag.

[Joe L.]

Re: 1971 Fuel Cap Restoration - Recommendation(s)

Joe,

A couple years ago you posted the current service part replacement is identical to the original and not very expensive. So I purchased one for my '70. It's not in front of me but it looks like the '71 in the photo sans the red caution tag.

Mark------


I think I was referring to the 1969 cap which was also SERVICE for 1963-68 after May, 1969. The primary difference between the 1964-67 cap, GM #3843576, is the gasket which is "paper" versus the 1969 cap which has a rubber gasket. I do not know how the 1968-only cap, GM #3921689, differed from either the 64-68 or the 1969 cap, GM #3952708. The 3843576 was discontinued in July, 1968 and replaced for SERVICE by the 3921689. The 3921689 lived a very short life and was discontinued and replaced by the 3952708 in May, 1969. I'd be very interested in seeing a photo of a known-original, 1968 only GM #3921689.

Below are photos of my original 1969 cap, a GM SERVICE #3953708, and a Stant replacement cap. The only difference I can see is the tiny Stant logo embossed on the underside of the cap.




The 1970 cap which may have been used into 1971 was GM #3974743. I now THINK that this was probably the same as the one pictured above but without the red label. It was discontinued from SERVICE in July, 1973 and replaced by the 1972-74 cap, GM #3994339. The 1971 cap was GM #3983384. I suspect it is the one pictured above. I don't know of a reproduction of the 3974743 or 3983384 cap although there may be one. The only visual difference I note between the 3974743, 3983384 and the earlier GM #3952708 is the embossment and the label. Of course, the 3974743/3983384 caps are functionally different from the 3952708 and, thus, not interchangeable.

The 1972-74 cap was GM #3994339. I don't have an original example of one of these caps but I do have a GM replacement as well as a Stant replacement. The GM cap has a very light chromate overplate while the Stant has a much heavier chromate overplate. These can easily be removed with a dilute acid solution. I'd be very curious to know how these caps differ from the originals other than, presumably, the embossed Stant logo on the underside.




One other "side issue": if one has a a 1963-69 Corvette with a GM SERVICE fuel tank purchased after 1970, it will incorporate an integral pressure-vacuum valve. GM instructs that when such a tank is used, the fuel cap should be changed to the sealed GM #3994339. I HIGHLY recommend that this be done. You can always install an original cap for judging.

[John S.]

Re: 1971 Fuel Cap Restoration - Recommendation(s)

Contact Joe Perri - he is in the Driveline on pg 39. Joe is the best and does excellent work.

[Mark E.]

Re: 1971 Fuel Cap Restoration - Recommendation(s)

Thanks Joe. Your post is detailed and helpful as usual.

I got the #3994339 from RockAuto.com for $29 based on your recommendation a few years ago (I wish I could find that post of yours). The photos below are from their website. As you mention, the embossed Stant logo on the underside may be the only difference from original. My original cap is in storage so I can't compare right now but I do remember at the time the new cap was virtually identical.

For use with the OP's '71, can the red plastic tag be transferred to the new cap? For the price and convenience, this may be a good option (24 month warranty too). The configuration deduction for the Stant logo should be a dot, if noticed at all.

I'm amazed a service part like this for a low production, 50 year old car is available at all.

[Joe L.]

Re: 1971 Fuel Cap Restoration - Recommendation(s)

Thanks Joe. Your post is detailed and helpful as usual.

I got the #3994339 from RockAuto.com for $29 based on your recommendation a few years ago (I wish I could find that post of yours). The photos below are from their website. As you mention, the embossed Stant logo on the underside may be the only difference from original. My original cap is in storage so I can't compare right now but I do remember at the time the new cap was virtually identical.

For use with the OP's '71, can the red plastic tag be transferred to the new cap? For the price and convenience, this may be a good option (24 month warranty too). The configuration deduction for the Stant logo should be a dot, if noticed at all.

I'm amazed a service part like this for a low production, 50 year old car is available at all.

Mark-------

The GM #3994339 is the 1972-74 cap although I suppose it might have been used in late 1971. This cap is configured differently than the 1970-71 caps I described above. So, adding the label to this cap wouldn't fool anyone.

As I mentioned, though, the 3994339 is SERVICE for 1970-71 after July, 1973.

[Mark E.]

Re: 1971 Fuel Cap Restoration - Recommendation(s)

Thanks for clarifying Joe.

Looking at the photos, one difference I see is the scalloped vs smooth outer circumference.

Maybe my "original" cap was also a replacement?

[Joe L.]

Re: 1971 Fuel Cap Restoration - Recommendation(s)

Thanks for clarifying Joe.

Looking at the photos, one difference I see is the scalloped vs smooth outer circumference.

Maybe my "original" cap was also a replacement?

Mark------


If you car is a 1970, I don't think it's possible your car could have originally been fitted with the 3994339. If it's a VERY late 1971, I'd say it's possible.

By the way, IF I said in my post of a few years ago that the GM #3994339 was the original cap for a 1970 or 1971, I don't know what I was thinking of.

[James G.]

Re: 1971 Fuel Cap Restoration - Recommendation(s)

My 71 built on the last day has the RED LABEL on the cap... no reason to suspect it was changed as the owner from 73-2016 stated it with the car the day he bought it.
Visible here when I pulled the tank down for the sheet.

[Joe L.]

Re: 1971 Fuel Cap Restoration - Recommendation(s)

My 71 built on the last day has the RED LABEL on the cap... no reason to suspect it was changed as the owner from 73-2016 stated it with the car the day he bought it.
Visible here when I pulled the tank down for the sheet.

James-----

I agree; it's VERY unlikely that this cap wound up installed on the car post-factory. So, that could also mean that this cap was possibly installed on some early 1972's rather that the 3994339 being installed on late 1971's. There's absolutely no functional reason why the 3983384 could not have been used on early 1972's.

[Steve B.]

Re: 1971 Fuel Cap Restoration - Recommendation(s)

Contact Joe Perri - he is in the Driveline on pg 39. Joe is the best and does excellent work.

Agree 100% Joe is the best.

[Ray K.]

Re: 1971 Fuel Cap Restoration - Recommendation(s)

Thanks everybody for your recommendation and insight.

I sent Joe JPEGS of my fuel cap and he agrees that it can be restored. Cost is very reasonable when compared to the "aftermarket" non-original one being sold by Paragon (with a Open Slowly Caution decal, instead of the metal one). I sent it to Joe this morning and I'll post restored JPEGS when it returns.

Ray K