this isn't going to apply to very many people... but if you need parts for the 440 six pack, here's some links and a couple of cool vintage parts packs

http://www.chicagocarburetor.com/carburetor-parts.php?c=2354

the damn accelerator pump is leaking like crazy on my carb

or the rebuild kit (not available through Holley) https://www.jegs.com/i/Holley/510/37-396/10002/-1

there's a couple of sites that just seem to be search engines
but they're turning up stuff that Google isn't
http://www.stevefairchild.com/parts/holley-six-pack.html
http://www.glasshouseauto.com/section/six-pack-carbs.html
These sites have some nice sets of things you might want for a restoration, like a kit of just the plate shaft complete, or the inlet fuel filters

it turns out the float bowl to metering plate gasket wasn't the leaking part, the accelerator pump gasket is... so, time to tear it all apart again, and this time, maybe I'll get that damn leak fixed.

Why's it leaking? Well, it might be the 50 year old gasket, or that I only run the engine about once or twice a year, or the addition of alcohol to gasoline, which people say is messing up all the old rubber gaskets. That's a couple possibilities.

so, fyi, if you haven't yet had to replace gaskets, go for the green new ones

The things you ought to know, it's a 2300 series carb, and though specifically always carries the #4144-1, Holley never gives it any recognition, as though it doesn't exist. 

So, when you want to see an engineering drawing on it, expect no fucking help at all from any Holley resource. Go to the car guys, like Old Car Manual Project

 which if you compare to what https://www.holley.com/support/ offers, some how that isn't appearant on their website, but showed up in Google Images:

http://www.oldcarmanualproject.com/manuals/Carbs/Holley/TypicalViews/pages/2300C-SixPack.html

see what I mean?

you'll see that Holley has no made no effort to be useful, you know, after you've spent 1500 dollars or more on their carbs. Face it, these 6 packs are about 700 per carb, and the intake adds another 500. You're looking at 2500 dollars for a working 440 six pack. 

Carb Number      Carb Model Number     CFM         Renew Kit       Trick Kit

R4144-1              2300                              350            37-1537           37-933

 https://documents.holley.com/techlibrary_carb_numerical_listing.pdf

But what if you'd like to know about which accelerator pump is what you're using?

A larger capacity accelerator pump achieves one thing, it extends the duration of the pump shot.

 A larger accelerator pump is usually required when the carburetor, intake manifold and/or cylinder head is too large for the engine and the resulting weaker signal at low engine RPMs requires more time for the booster venturi to pull fuel through the main jet.

The 30 and 50cc capacity is the volume of fuel displaced from the accelerator pump in 10 complete strokes of the pump arm.

So the actual capacity is 1/10 that number or roughly 3 and 5cc respectively when opening the throttle from idle to wide open.

 The larger capacity 50cc pump is easily recognizable by the large pump arm with the encapsulated spring. In addition, the 50cc pump also uses a larger pump cam either a brown color (conventional carbs) or a yellow color (model 4500).

https://www.holley.com/blog/post/carb_class_giving_the_bog_the_boot/

Well, in my search for answers, I did find that it's taking a lot of time to find info, but I found this

and though the 440 six pack Mopar page is dead... the other pages, catalog scans, etc are amazing