Strange looking six pack setup

[ed-pv]

I did some parts swapping with a friend this weekend and ended up trading some big block Chevy stuff for this setup.  He is not a MOPAR guy and had no details on it other than the previous owner planned on putting it into a 70 Cuda, but later put a big block in. 

The base of the air cleaner is a fiberglass repo, but the rest of the parts look to be original.  What confuses me are the outboard carbs.  I have seen the stock vacuum secondaries and have even seen the mechanical secondaries, but these carbs have BOTH the vacuum cans AND the mechanical setup on them.  The outboard carbs even have the accelerator pumps on them!  The vacuum cans are not connected so the mechanical linkage operates the secondaries, but why would these carbs have both??

[734406pk]

A very nice set up to start with, but the mechanical over vacuum set up should be removed. I have no idea what the PO was  thinking...

[ed-pv]

Can I run it this way since the vacuum pods are disconnected?  I would assume the mechanical linkage will open the outboard carbs and the vacuum pods would have no input.

[1 Wild R/T]

Try putting fuel in an end carb & operate the accelerator pump to see if it works... List 4790 is a vacuum outboard with no accelerator pump, obviously the linkage & float bowl plus a squirter nozzle have been added, question is did the guy drill passages too....

Before attempting to run it the collet that forces the secondaries to close needs to be set, currently once you open the outboards they won't shut & that could get exciting....

I'd play with it & see how it works, might run real well with enough gear & some tuning.... Hopefully the guy that was gonna put it on his 70 Cuda didn't dump it cause he couldn't fix what he'd screwed up....  Worst case go back to vacuum....

[mopar jack]

I agree with 1 wildR/T. make sure the secondaries close when the primary closes. Since this looks like a heavily modified system, I  would check the kill bleed ports for the vacuum secondaries. Racers would plug the port for all out racing and render them useless for the street. however the mechanical outboards may bypass that. There is a good article by Doctor Jerry Binder on six packs attached. http://www.mopar1.us/6barreltips.html towards the bottom there are seven pages listed, open to read his article.

[ed-pv]

Thanks for the input guys!  I put some fuel in the outboards and the accelerator pumps on both outboards work great!  Just like a double pumper!  The outboards do close when at idle and if i adjust the slide collet on the bottom side, they will be forced closed at idle.  Kind of looking forward to getting it on a car to see how it runs!  I have a 440 six-pack with mechanical secondaries that runs great!

[Chryco Psycho]

It shoud perform very well then if the accelerator pump all work , not sure why the vacuum pots were even left on 

[ed-pv]

It shoud perform very well then if the accelerator pump all work , not sure why the vacuum pots were even left on 

Yea, the vacuum pots are not really doing anything at this point, but I may just leave them on so I can keep track of them

[DocMel]

I've been around sixpack and six barrel setups, and tripower (gm speak) holley set ups

Original setup (vacuum outboards) in both sixpack and tri power setups, when at WOT, dont give a "kick in the pants" feel that most expect.  When the outboards are opened by vacuum, you get more of a gentle push into your seat, than a "slammed into the back of your  the seat" feel. That's just the nature of vacuum operated outboards 

So, some modified the outboards to mechanical to get more of a perceived response

I stay away from these setups, because who knows what else has been changed that you cant see