any 6 pak gurus out there?

dust-u said
hoping someone can help me tune this gd sixpack. I have a 72 340 duster 340 plus 30.. comp cams 274h cam. here is where it gets interesting . the motor has 12.5 slugs . in trying to reduce the comp ratio it has cometic head gaskets .083. thick and a set of open chambered 318 heads with 188/160 valves. I cant remember what the cr actually is ? ANYWAY THE SIX PAK IS BRAND NEW.the only changes made were minimal. the center jets were changes out from 62s to 63s. the motor runs 8 in vacuum. and it has a 4.5 power valve. I have the initial timing at pretty much where it wants and @3000 36 degrees. the outboard carb idle screws are 1/8 out. I can get it to idle but clearly can tell it is rich. can anyone offer me a place to start. ? I really want to run the sixpak but in all honesty it ran great with a holley 770 street avenger and an ld340 intake.. beyond frustrated.please help?

I never liked the way the vacuum operated outboards feel while driving, so I have always run the Direct Connection mechanical carbs. They are much easier to tune and have no idle circuits in the outboards, a feature the factory used to keep the fuel from going stale in them if they are not opened for a long time.

Its difficult to get all six idle circuits perfectly balanced, especially if you are only guesstimating by counting the turns of the screws. Mechanical secondary carbs don't have that issue. You need to be able to turn the screws while the motor is running to find the spot where they induce lean misfire while turning them in, and then back them off 1/2 to 3/4 of a turn from that. It takes a few trips around the 6 screw adjusted circuits to get them balanced and correct.

Promax makes a nice baseplate to make it easier to adjust the idle circuits while the motor is running.

How did you determine your initial timing, and what is it currently set at?

Have you sprayed carb or brake cleaner around the manifold, vacuum lines and carbs to verify no vacuum leaks?

Invest in a wide band A/F meter and get it set-up in your car. It will make dialing in these carbs much easier.