It's hard to diagnose via the internet as we can't see or hear the operation of your set up, along with just the supplied info on hand, that being said I like to start with the basics to sometimes cover the most obvious often overlooked, you gave no mention of checking/setting fuel level in each bowl, to me this is the first operational/running step after confirming all mechanical installation procedures...
I'll mention this just for sh!ts and giggles: but I've come across 2 guys so far over the years that either daunted or unfamiliar with the set up, that have installed the center carb as delivered new from Holley, unfortunately Holley attaches and clips a hose from the PCV port to the bowl vent tube (why?), yeah the set up runs! (barely), but the PCV "vacuums" the bowl dry of fuel... it's simple problems like this that can cause some to render " complex solutions to simple problems", you/we need to know that all of the basics from installation to operational set up have been performed
Mike
Thanks Mike. I did fail to mention couple things. All 3 carbs are original 70's, the main body was slightly warped and was milled. There was a leak in the power valve bowl as it was not holding vacuum but since the milling, its holding vacuum now. The pcv port is located on the bottom. I will post a picture of the setup later this afternoon. I think I will also post a video and attach a link so all of you can better see my dilemma.
Far as the fuel level float is concerned I have messed with this many times. its currently set at half meaning basically fuel dribbling over the sight hole, if I lower the fuel level any farther, engine will not respond very well. I think I have this dialed in correctly.
One thing I was told to check was the fuel pressure. I am currently using mechanical Holley high volume 8 psi. Everything I read says use 6.5 fuel pressure regulator but does 1.5 pressure make that much difference?
Everyone I talked to says a vacuum leak somewhere.. One thing I have not triedis trying out a difference pcv valve. Could this cause too much air?
That duration cam of a will need a ton of initial advance. I would block the power valve if you suspest it, JUST TO GET THE IDLE RIGHT, DO NOT DRIVE!! It sounds like your outboards are a little rich at idle by your description, and the center is not doing much. The idle fuel feeds in the center metering block could be plugged. I have fixed a similar problem by finding a metering block that I can see the brass idle fuel bleeds in, so I can add more fuel, .001 at a time. Most stock 6bbl blocks have hidden feeds, so no dice there. 8 psi could overpower the floats, pull the sight plugs and see. The fact it will not idle without the choke tells me it is lean, meaning power valve ok, could be pcv valve, likely a mixture problem. Sometimes lean smells rich to most people. A few things to check
Front carb
.078 throttle blade holes
.055 idle air bleeds
#34 metering plate with .036 idle fuel bleeds .089-.089 jets
Rear is same with#35 plate .036 idle bleeds .086-.093 jets
Center .078 throttle plate holes
.068 idle air bleed
Make sure someone has not drilled any of those, and the metering plates are 6bbl #34-35, the new replacments are not the same.
Mine idles clean with an old .509 mopar cam, I know outdated junk, stock plates, 3/8 turn on the
outboards, 1-1/4 on the center, and those stock drill sizes I listed. 3.5 power valve, 64 jet and a 4-speed. If I go 1/2 turn on the ends it gets stinky. I need a choke to start it, none once it is warmed up. It will die if you turn 1 center mixture screw in, so it is close.
