GF 90 - Fuel Filter questions

[Oliver S.]

I've got some questions regarding the GF 90:
As far as I know the original GF 90 has a notch at the 'hex nut'. Am I right?
The GF 90 AC Delco replacement is not only silver but it also has other measures. Can it be installed without problems? Can the original clamp mounted on the engine be used?
Has anybody had leaking problems with the GF 90 'authentic' replacement filter - those without the notches? On my one the crossover where the hex nut is fixed to the filter is grubbily done.

Regards
Oliver

[William C.]

Re: GF 90 - Fuel Filter questions

There were several versions of the GF-90, so you have to know what era we are discussing, the '62 version was silver, with no "notches" and I don't know when the "notches" appeared, but It may not have been until after the production run of the first design Black parts was completed. (IE-Service)

[Michael H.]

Re: GF 90 - Fuel Filter questions

The GF 90 AC Delco replacement is not only silver but it also has other measures.

Oliver,

I don't have the details on the grooved/non grooved fitting but I can tell you what color filter was to be used on 62-65.

For 62, it appears that all came with a silver GF-90 filter.

For early production 63, the filter was silver, same as 62. Around the 1st of the year 1963, the filter was changed in production to black w/white characters.

The same assembly line black/white filter was called out for the remainder of 63-65 production.

This info comes right from GM. It also agrees with many many factory photos of new 62-65 cars.

[Joe R.]

Re: GF 90 - Fuel Filter questions

I can't wait for this thread to unfold!

I have no dogs in this so I'll wait until the end.

JR

[John D.]

Re: GF 90 - Fuel Filter questions

Oliver, If you want to fly thru the judging processs go with the new repro. Now if you are concerned about fittings leaking use Loctite 545 on them and you can rest assure you won't have any leaks.

Now for a wrench into the above literally speaking. I do believe you might find out here that the 65 black filter could have had a hint of a notch on the hex from the factory.
The earliest NOS AC GF-90's I have seen are silver and they have just a hint of a notch. The later SR's ALL have a notch. The later the filter was made the deeper and more pronunced the notch.
The repro made by Brian of Corvette Specialities of MD is a wonderful GM licensed part. I have one on my 63 FI car-March car and haven't gotten any dings with it. JD

[Stuart F.]

Re: GF 90 - Fuel Filter questions

Might be worth checking the archive on this subject. Seems we were down this road a few months back including pictures which showed not only notch vs. no notch, but differences in white lettering size/fonts, etc.

We're off to the races!

Stu Fox

[Wayne M.]

Re: GF 90 - Fuel Filter questions

Oliver -- a VERY controversial topic. Here's some links from last year (April to Aug), with pics and commentary.: Here's the links to save everyone time.

https://www.forums.ncrs.org/showthread.php?t=59743&highlight=GF-90&uid=8493

https://www.forums.ncrs.org/showthread.php?t=60473&highlight=GF-90&uid=2668

https://www.forums.ncrs.org/showthread.php?t=62946&highlight=GF-90&uid=8289

Some posters have very strong opinions, is all I'll say.

[Oliver S.]

Re: GF 90 - Fuel Filter questions

The one that was and is installed again has deep notch hex nuts. Therefore I was curious if it may be the initial one since I was under the impression that later replacements were without the notch. At least it looks very old. I wasn't aware that this is so complicated .

The final question to me is, if the AC DELCO GF 90 with bigger diameter can be installed with the original clamp mounted on the engine and if there may be problems with the fuel line alignment. Today, when reinstalling the old one I haven't had the AC DELCO at hand to try. But next time I want to be prepared.

Regards
Oliver

[Timothy B.]

Re: GF 90 - Fuel Filter questions

Oliver, The new service replacement AC filter is larger in diameter than the older GF 90 and will not work with the old clamp. There should be a larger clamp in the box with the new filter.

[Michael H.]

Re: GF 90 - Fuel Filter questions

Does anyone happen to have a 62 AIM handy? If so, is the fuel filter for 62 FI cars shown? What's the part number? Thanks.

[Michael H.]

Re: GF 90 - Fuel Filter questions

I've got some questions regarding the GF 90:
As far as I know the original GF 90 has a notch at the 'hex nut'. Am I right?

Yes, you are correct. This is a picture of a totally untouched 1500 mile original 65 with a black GF-90 and it has the groove.

I don't know if ALL GF-90's from the era had the groove but this one sure did.

[Duke W.]

Re: GF 90 - Fuel Filter questions

Oliver,

I don't have the details on the grooved/non grooved fitting but I can tell you what color filter was to be used on 62-65.

For 62, it appears that all came with a silver GF-90 filter.

For early production 63, the filter was silver, same as 62. Around the 1st of the year 1963, the filter was changed in production to black w/white characters.

The same assembly line black/white filter was called out for the remainder of 63-65 production.

This info comes right from GM. It also agrees with many many factory photos of new 62-65 cars.

I agree. Though long gone, the original GF-90 on my March production '63 L-76 was black, but I don't recall if it had the notches in the hex.

Duke

[John D.]

Re: GF 90 - Fuel Filter questions

Yes, you are correct. This is a picture of a totally untouched 1500 mile original 65 with a black GF-90 and it has the groove.

I don't know if ALL GF-90's from the era had the groove but this one sure did.

Thanks Michael, Nice to see that fine pic again. JD

[Michael H.]

Re: GF 90 - Fuel Filter questions

Thanks Michael, Nice to see that fine pic again. JD

Just to add more confusion, here's a shot of a pilot line 63 engine. Note, silver GF-90 filter with no groove. Same silver/red GF-90 that was used on 62 FI cars.

I ask earlier if anyone had the 62 AIM part number for the GF-90 but no response. Pretty sure it will be the same as the early production 63.

[John D.]

Re: GF 90 - Fuel Filter questions

Just did a search to bring this subject on notches up again. Didn't want to start another post. More of us should use the search feature. Me included.
Today our Pittsburgh chapter had a really great judged chapter show. One thing that caught my eye was a 63 automatic car that had the original fuel filter on it. The filter had NO notches. Now as to whether it was silver or whether it was black was hard to tell as it had been roughly painted over. I believe the car was in the 16,000 range. NO notches. The owner was very proud of the fact the GF-90 filter was original. John D.