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New 6 bbl, what are the best upgrades

69 GTX

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I just bought a all new 6bbl set up from jegs. I ordered the 71 carbs. So I'm thinking I need the promax rear throttle base with outboard idle screws & metering plates with jets. Do I need a 50 cc accelerator pump? That used to be standard upgrade on the 4bbls. Anything that'll make my task of tuning easier would be helpful. Still looking for a A12 base plate to finish everthing up.
 
I just bought a all new 6bbl set up from jegs. I ordered the 71 carbs. So I'm thinking I need the promax rear throttle base with outboard idle screws & metering plates with jets. Do I need a 50 cc accelerator pump? That used to be standard upgrade on the 4bbls. Anything that'll make my task of tuning easier would be helpful. Still looking for a A12 base plate to finish everthing up.
i've had lots of 6bbl stuff and i'd never do any of the things your looking at. the worst advice you can get is on these websites. 6bbl's don't need to be a money pit or re-engineered.
 
"New 6 bbl, what are the best upgrades"

A 4 BBL! But seriously, these can be frustrating to work on. Just a long way into them for a simple jet change.
 
I thought I'd be smart too and put the 50cc accl pump in my Six Pack, BIG mistake. Took that right out and stayed with the stock 30cc pump.
 
The only upgrade that's worth it is changing the black rubber part (to red I believe) to handle the POS gas we have now.
 
I know they are going to be a pain to get dialed in, but in order to meet my MPG goal didn't see any other way. Besides that is what I wanted. These will see some strip action also.
 
You've already spent a ton on this stuff, run it first before spending more. I had several setups with '69, '70 & '71(which I never really ran) carbs on the Edelbrock manifold. Mine ran great with stock jet plates in the end carbs, 30 cc accelerator pump. The modifications I made were: an adjustable needle valve in the vacum supply to the end carbs to allow adjustment of the opening point, richening the idle screws in the end carbs, tuning the jets in the center carb 1 or 2 jet sizes as I recall, and the accelerator shooter size, trying the different secondary springs. This was on a 446" - 11.5 - iron head, 300*/.585 cam motor. Just adjusting the idle screws on the end carbs made a ton of difference. Run it 1st. I'm convinced that most of the drivability issues back in the day were from those end carb idle screws being too lean & not having the right opening point & spring rate on the secondaries. BTW the '70 carbs ran better for some reason.
 
Thanks 66. My plan is to try and run the engine on the dyno before instaling in the car. So I may go ahead with the jetted metering plates & jet them to OEM to start. And the rear throttle plate with angled idle screws so I won't have to remove the rear carb to make adjustments. As you know Dyno time isn't cheap so the quicker I can make adjustments the better. My combo will be about the same, 446 10.5 with milder cam.
 
i dont really see the need for the trick baseplate. once you get it set your not going to mess with it. what i would recommend is a braided fuel line set from promax, makes carbs on and off so much easier. and when you adjust the rear baseplate screws, you can just take the carb loose and swing the carb back and not even undo the fuel lines. very quick process.

 
i dont really see the need for the trick baseplate. once you get it set your not going to mess with it. what i would recommend is a braided fuel line set from promax, makes carbs on and off so much easier. and when you adjust the rear baseplate screws, you can just take the carb loose and swing the carb back and not even undo the fuel lines. very quick process.


Oh, there is some trickery going on here. Had we not talked some time ago I would have continued too over look it but now that I know, it is sticks out like a sore thumb... And I won't let the cat out of the bag......
 
i dont really see the need for the trick baseplate. once you get it set your not going to mess with it. what i would recommend is a braided fuel line set from promax, makes carbs on and off so much easier. and when you adjust the rear baseplate screws, you can just take the carb loose and swing the carb back and not even undo the fuel lines. very quick process.


Exactly WTF kinda six pack set-up is THAT?!
 
Its started as a six-pack and its still every bit a six-pack, but one needs too look past the braided steel fuel lines and the removal of the air horn choke tower and not be distracted. Its right out in the open for all too see its that sneeky, you have too look real hard but its there right out in the open none the less....... That's all I will say until the owner comes clean if he so choose too do so, I will respect his covert shenanigans..... If he has the Mopar faithful this stumped the Bowtie brigade are surly to be clueless.

I bet it pulls at the midrange and has a top end charge unlike any other six-pack on the road, that's the only hint I will give.
 
Wish I could zoom in to see better.
 
I rebuilt a 6 pack setup back in the early 90s, I bought the carbs used, cleaned them installed Holley gaskets, and jetted it according to the old Direct Connection / Mopar performance bible, Played with the secondary springs (went with the purple ones), set my Mopar Electronic distributor to 34 degrees and never looked back My car was a 4 speed, and I never even looked at the carbs for the next 9 years of driving. My car had a Hemi grind cam, and a 4 speed I will look th see if I still have the old book around for specific jet #s. I never understood people complaining about how they were hard to tune and all They are nothing more than a Holley 4 barrel cut in half with one extra set of secondaries. Don't try any "tricks", just keep it simple. Another thing I realized is a lot of the problems stem from stale gas in the outboard carbs, they do have idle circuits to move the gas through, but if the car is not a daily driver, and you don't often put your foot in it the gas (Especially today's crap) will go bad, and cause issues.

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I found it:

I know first hand this works with A Hemi grind cam, stock manifolds, 2 1/2" exhaust and the stock air cleaner, it ran strong and never fouled plugs, bogged, or hesitated, it just pulled



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- - - Updated - - -

I do know with the Carbs set this way if I ran 100 Octane race gas with lead, my tailpipes would be light grey, almost white after a long highway run, and I would pull 14-15 MPG on the highway running 75-80 MPH
 
I do know with the Carbs set this way if I ran 100 Octane race gas with lead, my tailpipes would be light grey, almost white after a long highway run, and I would pull 14-15 MPG on the highway running 75-80 MPH

And what gears?
 
3.54 and 27" tall tires

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Top speed I ever reached was 145 limited by 6400 RPM...
 
Thanks, I've always heard the 6 BBL could get that sort of mileage by running on the smaller 2 BBL center carb most of the time and the right gear and tire height
 
I rebuilt a 6 pack setup back in the early 90s, I bought the carbs used, cleaned them installed Holley gaskets, and jetted it according to the old Direct Connection / Mopar performance bible, Played with the secondary springs (went with the purple ones), set my Mopar Electronic distributor to 34 degrees and never looked back My car was a 4 speed, and I never even looked at the carbs for the next 9 years of driving. My car had a Hemi grind cam, and a 4 speed I will look th see if I still have the old book around for specific jet #s. I never understood people complaining about how they were hard to tune and all They are nothing more than a Holley 4 barrel cut in half with one extra set of secondaries. Don't try any "tricks", just keep it simple. Another thing I realized is a lot of the problems stem from stale gas in the outboard carbs, they do have idle circuits to move the gas through, but if the car is not a daily driver, and you don't often put your foot in it the gas (Especially today's crap) will go bad, and cause issues.

- - - Updated - - -

I found it:

I know first hand this works with A Hemi grind cam, stock manifolds, 2 1/2" exhaust and the stock air cleaner, it ran strong and never fouled plugs, bogged, or hesitated, it just pulled



- - - Updated - - -



- - - Updated - - -

I do know with the Carbs set this way if I ran 100 Octane race gas with lead, my tailpipes would be light grey, almost white after a long highway run, and I would pull 14-15 MPG on the highway running 75-80 MPH

Are you sure you weren't driving my bird ??:icon_eek:
 
Are you sure you weren't driving my bird ??:icon_eek:

While it was a Superbird that was originally Vitamin C, mine was painted Petty Blue by the dealer before it ever sold.

This is a pic of my car 2 owners after me...

I sold it to Dave Kanofsky in 1997, he sold it to the Big Kahuna in Texas, and last I heard it was in NY, but it was for sale again for 275K

And the 145 MPH was driving down I 65 to the Mopar nats drafting with a couple friends in their birds, another 6 BBL and a Hemi...
 
i dont really see the need for the trick baseplate. once you get it set your not going to mess with it. what i would recommend is a braided fuel line set from promax, makes carbs on and off so much easier. and when you adjust the rear baseplate screws, you can just take the carb loose and swing the carb back and not even undo the fuel lines. very quick process.


is that a 500 cfm center carb?
 
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