Although its been a couple years since my last posts on this subject, I eventually got the six-pack running very well... vacumm, idle, floats, timing... repeatedly checked and tuned (took about 2 hours).. runs awesome! I do have the entire Promax setup (center metering block, f/r plates, and rear adjustable base plate. I'll give credit to my couple friends (Greg Bosak, and later David Jahns-SCCA Pro TransAm road racer).

Tom,
I understand you know how to tune 6 oaks ? I installed the Promax setup on my 2300 holleys. I bought the car 3 years ago. I rebuild the carbs recently. I installed 68 jets in center and 88 in the outboards per Pro max . The center carb has no choke. The guy took it off for racing. I live in Texas so cold weather is not an issue. I won't drive in bad or cold weather, not worth the risk.

Vaccuum gauge reads 9. I adjusted the fast idle so it will idle . I set the mechanical advance at 18 degrees which is the lowest I can go with an MSD. I set initial timing to 19 degrees. After warming up, the idle drops to 500 or so and then I have to up the fast idle screw to keep it idling after awhile the idle will go from 900 to 1350. I have the promax angle rear base plates. i set both forward and rear to 1/4 turn and center to 2 turns. I sprayed WD 40 around the carbs looking for a vacuum leak; no change in idle so I assume there are no vacuum leaks. The only original mixture screws are on the front. Everything else is new( center and rear). 180 degree thermostat, Bullitt cam, 18 in 17 ex lash settings hot; I set both to .012 cold. Engine starts right up; electric fuel pump with 6 psi pressure. 6.5 power valve. The car has backfired several times initially before I got the timing and lash reset. I have checked the timing and lash 2 times.

The idle again wanders; Any suggestions ?

I am good at guessing....
You are over jetted on the primary carb
Try starting at 64

There may be a blown pwr valve from the backfire
If you have 9 hg of idle vaccuum use a 6.5 pwr valve

Did you review the ctr crb set up and check the "slot"?

Needs a 195 degree thermostat

One sure way of telling if the outbard carbs are opening or not is to disconnect the vacume hose from the center carb tha goes to the outboard carbs and go drive the car, if it loses a bunch ofpower from when hook up there working. If there is no change there not opening, make sure the hose to the outboards is hook up to the vacume nipple on the carb and not on the metering block Please let us know what you find out Good luck