Any Carb Gurus out there want to comment?

[elmariachi]

My 427 FE has a similar cam profile as your engine. I am at 10:1, I run 18 initial and 36 total and my Powermaster starter spins my engine like a running chainsaw. If it were me, I would start by setting the total time to 34 degrees all in by 3k. I would then lock out the advance and set the idle timing to 18 and bolt it down and not touch it again. (You can come back later after all the carb tuning is done and experiment with a little more total timing, provided you don't let that bump up the initial timing and alter your idle.) Then I would remove the carb and make sure (based on your 9" vacuum reading above) that you have nothing larger than 6.5 power valves installed, and confirm that both transition slots are square. Open the mixture screws 1.5 turns, put the carb back on and work to get it to idle just under 1k rpms. I would use the vacuum gauge to tune the mixture screws for max vacuum, and then open the mixture screws another 1/8-1/4 turn from max vacuum. After all that, I'd unlock the advance and work on using heavier springs first and experimenting with lighter spring combos to get to an advance curve that feels good in the seat of your pants and doesn't affect idle. If all that doesn't work, then its time to either have that carb looked at or try another carb with which to make some comparisons and decisions.

Unless they are plugged, I cannot imagine air bleeds causing any of your problems and I don't think its a cfm issue at all.



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