I just bought a 71 Challenger with a 440 Six Pack in it. but the linkage has been changed to mechanical and the outboard carbs have both vacuum pots and accelerator pumps on them. My question what do I need to do or change besides the linkage to put this back to stock or am I better off just buying two new outboard carbs?


Can post more pictures if needed.

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If it runs good, leave it. If it's a restoration, get two new carbs.

There are no vacuum lines connecting the three carbs for starters. Vaccuum dashpot parts and correct linkage is still available (Holley and/or Chrysler). Looks like its running pretty rich.

Do the accelerator pumps work on the end carbs? The mechanical linkage effectively overrides the vacuum diaphragms functioning. If those are original vacuum secondary carbs then someone has done some serious modifications to them to use an accelerator pump. What are the list numbers on the carbs?

Agreed, looks like the kit from "6 packs to go"...There was some serious mods done to the end carbs for that kit...Back then you could send them to the guy or if you had a business {as in licensed not the home garage/basement rebuilds} he'd send you the parts so you could do it in house...We did a few back then and man what a difference the manual linkage and mods made !!! You'll need to dig into the carbs to see just what you've got there....You should easily recoup the money needed for new end carbs and accesories by selling that kit...

Well the two outside carbs are 4672 and the center carb is a 4670 so they are the right ones. The only thing is this car is and auto car so out of the hole it falls on its face and then man it comes alive, if it was a four speed car I would leave it alone.So as for the questions yes the accelerator pumps work as do the the discharge nozzles, and the vacuum pots are hooked to the linkage and they are connected manually
I have attached a picture of how the vacuum pots are connected.

not familiar with this conversion but I have the article from mopar muscle when they did a spot on the six pack to go setup from Georgia, your linkage may need to be adjusted - I have the original mechanical carbs on my 440 and there is no delay or falling on face, just a tremendous rush and constant pulling after adjusting the stops on the linkage to where I like it. I'd almost say like fuel injection - just instant full throttle response when my right foot wants it. have a set of OE 71 carbs In I will be sending out for a restoration to Scott Smith at Harms Auto (sponsor here on moparts)when I get a box I can send all 3 in. these 4782 and 4783 carbs are fun though - even though the fuel lines and throttle linkage are on the same side(driver). looking forward to feeling how an OE sixpack setup works from the seat of the pants view on my car with auto trans after feeling how my friend 440-6 pack 4 speed feels when he tips in

Hesitation from the hole like that can also be due to the amount of the shot from the accelerator pump being too little and the initial timing in the distributor and what Rpm it kicks in. You can put a larger volume accelerator pump on the middle carb and change the nylon cam for a bigger shot. The stock distributor timing can't deliver spark fast enough to burn off the higher fuel volume. The correct combination however, is awesome!

I was thinking it was getting way to much fuel out of the hole because all three carbs have accelerator pumps.

I don't know but the secondaries are closed until the mechanical linkage kicks them in. You should have an extra spring pulling the secondaries back to hold them closed if you do not have vacuum hooked up to the secondaries.it makes the gas pedal kind of stiff but you know when you are kicking it. If you drive the car, I would adjust the mechanical linkage not to kick in until your cruising speed is over about 70-75 mph. That will be turning over 3500 rpms if you have a 4.10. The pumps on the secondaries are probably not kicking in until after your center carb has kicked in. If the secondaries are adjusted too
tight, it could be dumping too much too soon? If they are adjusted not to kick in too soon, you may need more of a shot in the center carb? Do you drag race it?

I just bought the car, it does have 4:10s right now but was going to change it to 3:55 to make it a little more drivable. Was not planing on racing it at all.

With mechanical linkage shouldn't the outer vac pots be disconnected from the linkage ???

Hello I have a set just like yours. I had them done by SixPack Performance years ago. For my 496 big block engine to work with a Paul Rossi SixPack intake (tunnel ram) If you or going back to stock carbs you will neeb all three carbs.Try to sell them to help you buy new ones.Your Distributor looks to be off some . The vacuum should be facing the battery not the carb.What year car? I have a NOS 1970 CARB, NUMBER IS 4144 new never had any gas in it or bolted to a intake. E-MAIL ME IF YOU LIKE . mosweethemi@yahoo.com