Technical Holley 94 secondaries sucking at idle

Check that your primary carb has functioning power valve it is common on some triple set up to block the power valve on the secondaries but it must work on the primary carb or you will be chasing a lean condition like you have that's why it get a little better with big main jets
standard power valve on a single carb engine is 7.5 hg that will never open on a multi carb engine
multi carb engines need somewhere between 3 and 4.5 hg

 

Your power valves and gaskets need to be checked for leakage and proper sizing.
To start with I would use 5.5 primary (center) and in the 3.5 secondaries (end carbs)

 

OK finally have some resolve.
After modifying the exhaust to fit the headers, looks like my exhaust leak is gone and engine actually idles smoother. Still bucking in lower rpms in gear so took out the 66`s and put the 57`s in with no change. Decided to go back to ported vacuum from manifold to see if that would help and bumped the timing to 17. Getting better and then adjusted fuel pressure back down to 3.5 psi. Slight bucking so reset mixture screws to 1 1/2 turns each and back until it stumbled. Getting better so 1/4 turn rich, test drive and a 1/8 more, stumble gone. Still after fire which I thought was backfire but not as aggressive as before. Will keep tweaking but it is the best it has run to date. Thanks everyone who posted for your help and tips.