1971 LT1 Fuel Tank Filler Neck

[Bob P.]

[Joe L.]

Re: 1971 LT1 Fuel Tank Filler Neck

I have a 71 LT1 and I’m in need of a new fuel filler neck. All the part suppliers are using the 63 to 67 convertible filler neck as a replacement. I would like to use the correct part, but I don’t know what the original one looks like, so I need some help with how I can identify one. It’s my understanding that the neck is longer than most others, but I don’t know how long it is or any other feature to look for. Thanks

Bob-------

The 71-74 filler neck is longer than the 63-67 convertible neck. However, the extra length only consists of a longer extension which is inside the tank. So, there is no external visual difference between the two filler necks.

There might be one other difference: the 1972-74 filler neck had a "restrictor" or "baffle" plate around the inner portion of the neck which effectively reduced the filler opening by about 1/2". I'm not sure if 1970 with EEC and 1971 had this feature. Some other members with original 1970 with EEC or 1971 will need to report.

By the way, all 1971 filler necks were the same regardless of engine option.

[Bob P.]

Re: 1971 LT1 Fuel Tank Filler Neck

Thanks Joe for the information. Does anyone have an idea of how long the filler neck is? If I had that length, from where the cap mounts to the bottom of tube it would give me something to identify one by.

[Bob P.]

[Joe L.]

Re: 1971 LT1 Fuel Tank Filler Neck

Thanks Joe for the information. Does anyone have an idea of how long the filler neck is? If I had that length, from where the cap mounts to the bottom of tube it would give me something to identify one by.

Bob-------


Attached are photos of an NOS GM #6262261 filler neck [not for sale]. This was the filler neck used from 1972 through 1974. I believe it's length is the same as the 1970 EEC equipped and all 1971 filler neck of GM #3972683 but I am not 100% certain of that. The length of the 6262261 is 2-1/4" from the bottom of the extension to the top of the fuel cap seal surface. It is 1" from the bottom of the mounting flange to the top of the fuel cap seal surface.

The 6262261 has a filler opening "restrictor" or "baffle" about 5/8" below the filler opening. I'm not sure if the 3972683 has this feature.

The 3972683 was discontinued in May, 1972 and replaced by the 6262261. The latter was discontinued without supersession in November, 1988.

By the way, all original fuel filler necks were terne coated, the same as fuel tanks.

It would be very helpful if some individuals with 1970 EEC or any 1971 could report on the configuration of their filler neck. These necks are not often replaced so there's a really good chance that any on the cars now will be original.

DSCN3760.jpgDSCN3761.jpgDSCN3762.jpgDSCN3763.jpg

[Bob P.]

B03F4194-5457-4AFB-9BB6-926582B2E102.jpeg

[Joe L.]

Re: 1971 LT1 Fuel Tank Filler Neck

Thanks again Joe! I believe you are correct, the length I think is the same 2.25”, although I haven’t been able to verify it yet. The difference between 6262261 and 3972683 is the restrictor or baffle. I have attached a photo I found of a ‘71 filler neck, but haven’t been able to verify the length of the extension. Maybe someone else will chime in to help. Then all I need to do is find one!!

[ATTACH=CONFIG]101185[/ATTACH]

Bob-------


Your chance of finding an NOS example is extremely slim. That's because it was only available in SERVICE for a relatively short period of time and was discontinued 48 years ago.

A used example can only come from a 1970 with EEC (California car) or a 1971.

[Billy S.]

Re: 1971 LT1 Fuel Tank Filler Neck

Bob here is a photo of the original tank with filler neck that I removed from my late 71 base motor car. If you would like photos of it installed in the car or measurements that I can take with it installed in the car let me know and I can do that tomorrow morning.

This is the best photo I have showing the filler neck from when I had to replace my tank.

IMG_20170501_183920edit.jpg

[Bob P.]

Re: 1971 LT1 Fuel Tank Filler Neck

Thanks for the photo. That at least confirms the picture that I had.

If you could get me some measurements that would be great! The most important measurement is the length of the neck from the bottom to the surface were the cap mates to it. Thanks again!

[Billy S.]

Re: 1971 LT1 Fuel Tank Filler Neck

Mine is a hair more then 2 and 1/4th inches tall

[Bob P.]

Re: 1971 LT1 Fuel Tank Filler Neck

Mine is a hair more then 2 and 1/4th inches tall

Thanks William! If you know anyone who has one let me know!