On of the things I’ve learned in this hobby is that you never stop learning. I’ve owned and collected six pack cars and parts since I bought my first AAR in 1976. I bought my six pack Superbird in 1982. I got into a discussion with Bill Overcash when I sent him my Superbird carbs years ago about the fuel inlet fittings. I sent him my three carbs that I pulled off the engine and never really touched them since I bought it. We had a discussion about the fuel inlet fittings at that time. He claimed that only the center carb had the odd inlet fitting that is round at the flange with the 11/16” hex vs the regular Holley with the 1” hex flange and the two 11/16” flats for tightening. I looked back on my pictures and my carbs had the round flange fitting on the front AND rear carb with the std Holley on the front. I’ve since worked on a 24,000 survivor six pack and it was the same. I just got in a set of assembly line AAR carbs that are the same way. I can see the purpose in this from Mopar. Those round flange fittings are much easier to get a wrench on for backup. Now I’ve got tons of original carbs I have bought but most have been messed with over the years. Frankly, I’ve just not paid much attention to that detail until recently. So, if some of you that have original cars with fittings could shed some light here, I’m all ears. The top photo is my NOS 70 center carb. The bottom has the regular Holley fitting . Thanks

Mark, I noticed the fuel inlets a few years ago and have been looking at survivor cars and ads for sixpack carbs since. Admittedly, I've been focused on Trans Am cars but I've seen multiple examples of the 440 cars as well. I've found examples with the unique inlet on all three carbs, two carbs, and singles. I don't have any documentation that would back me up but it just makes sense to me that Chrysler required a unique fuel inlet for their six packs from Holley. As you mentioned, because of the location of the fuel lines on the RH side (unlike the GM versions) they are very hard to get at. I have no idea if this also applied to the earlier A12 cars or if it came later. I've been looking at examples of Holley center-hung fuel bowls and have never found this type of inlet on anything other than a Mopar Sixpack carb.

Here are some survivor car pics as examples. I also have saved multiple examples from for sale ads of vintage set ups and individual carbs from C/L, eBay, etc. They are all over the place once you start looking.

A few more including the last one from a current eBay listing

And a couple more from online for sale ads

Attached are some images from the 1971 Service Manual. Hard to see but seems to show a mix.

Interesting pics from the service manual. I’ve learned not to rely on the pictures from there too much. Figure 1 is a 70-71 set because of the bowl vent hose on the center carb. You can’t see the fitting on the front bowl. However notice the rear fuel bowl. It has the correct level fuel level sight hole and the round portion that extends from the fuel inlet rearward.

Now look at the figure 35 picture. All three bowls have the Holley fitting, the bowl has the sharp line from the fuel fitting all the way to the sight plug AND the sight hole is way too high just like a Holley 4 barrel carb. It also has the 69 center bowl with the rubber to close the bowl vent. I bet that is a pre production picture for the service manual. Not sure what’s up with the center carb “sight plug “ arrow. I guess adjust the center float till gas comes out the top? lol!

Thanks for the thoughts and pictures. I think I’m going to conclude that the proper setup is for the center and rear MUST have the round fitting and the front CAN have the Holley fitting. I’ve personally seen three virtually untouched sets with that configuration. I know it’s much easier to work on the center and rear carbs with the round fitting.

Interesting learned 2 things Holley made 2 styles of fuel inlet fittings & six pack outer carbs have a lower fuel level.

Yes, and the latest released outboard carbs had higher fuel level holes with the, sharp line of coarse.

fastmark,
I posted about 440 Six Barrel fuel bowl inlet fittings several years ago.
It was over on DodgeCharger.com in the AERO car forum.
The post is currently on page 7 and the last reply is dated October 22, 2022.
I have a picture of my setup to start with the hex head fittings on the
outers and the smooth round fitting in the center.
MJ

I wonder if that was a running change @ Holley, or driven by assembly or servicing ?

I have a dim memory from 50 -some years ago that older Holleys had the rounded fittings before the hex style, which were of course easier to deal with.
That might explain the discrepancy in which/when.

There is a Holley fuel fitting currently available that looks similar but it takes a 3/8 fuel line and has a 3/4 hex head.

Again, I have no documentation but I have seen multiple survivor and take-off six pack setups with all three fittings. I realize car manufacturers would go to great lengths to save a few pennies but it sure would have been easier to direct Holley to use the same type of fuel fitting on all three carbs. My personal choice was to go with all three.

Well, I know it’s almost impossible to get a backup wrench on the regular Holley fitting if it’s on the center or rear. Without a backup, you can’t break the flair fitting nut. The front is easy with either.

I have several of those 3/8” lines. They may have been the Chevy application

Was this bowl not also used on early 70 models?

Is there a time frame that you noticed the center bowl vent tube introduced?

could a tubing wrench spend some time on a bridgeport, modifying it to fit the fittings ?
just asking, as i don't have any of these setups to visualize what may need to be done to get a back-up wrench in there.

A little extra work but doesn’t taking the carbs off front to back avoid all these issues?

Reversing the order to install them?

Yes, the change was about January 1, 1970. They still had the same rubber stopper as the 69. I do have a 70 440 carb at the shop with a 0220 date and it does not have the hot air idle that the emission carbs do so it may have still had the old bowl. I don’t know what bowl it had on it when I got it.

You still have to take the fuel line off to get to the bolts on the front carb. That’s the whole deal on a six pack. If you don’t back up the fitting, the flare will turn. I use a good Matco 11/16 open end on the hex for a backup and then a cheap ( because it’s a smaller diameter) line wrench on the fitting. The front carbs gets a 1” Snap-on on the big hex and a line wrench. I’ve got a set of old cut off fuel lines and some 5/16 hose for testing carbs. I test run every set of carbs I restore on my Cuda. I can change carbs faster than a top fuel pit crew! Lol. I’m doing lots of testing on a new metering block that’s easier to tune for a bigger cam with low vacuum.

I've owned many six pack set ups. I also restore carbs. Every original has all 3 carbs with hex fuel fitting. I've asked a manufacturer to look into reproducing them.

Thanks for the information. I’ve collected six packs cars and carbs since 1976 and have way too many of those hex fittings in my possession to just be on the center carb for sure. What puzzles me is this. I got my Superbird in 82. It was parked for several years before I got it and had an untouched original motor. I took many pictures. I looked back on them and only the center and rear had the hex fitting. I refreshed a set of “ almost untouched” six pack carbs from a 24,000 miles car parked since 74. It had the assembly line front and rear carbs but were swapped front to rear. The center carb was probably a factory replacement because it was dated about a month AFTER the car was built. It had the hex inlet on the proper front carb ( 4382) but the whole carb was in the rear position. It had all original gaskets in the carbs. Lastly I just finish refreshing a set of very low mileage 340 carbs with early dates, 0430, 0500, and 0650, and only the center and rear had the hex. He even had all the original fuel lines in good shape and all original gaskets.

I have learned in dealing with these cars that you never stop learning and you may never know the exact right answer. It does not make sense while they would make just one carb with a different fitting unless it saved a few pennies and Holley just did it that way. It could be a situation of what fittings they had on hand and had to get them out the door. Just like the decals on Superbirds. If they ran out of the correct color that was supposed to be on a cert color car, they just installed what they had to get them out the door.