hey guys, i have a 355 with a holley 650. heres the problem, sometimes from a dead stop it will bogg down under a full load.
i checked the timing, its at 12 degrees advanced. is this a carb problem, or do i need more timing. ( i tried more timing but then it dosent like to start when hot)

 

...Exactly.

Actually, you CAN get a Holley to run ½-ashed if you really want to, although I'm not sure why anyone would WANT to.

There are two typical problems that can casue this hesitation symptom. Weak ignition can cause misfire under load, and incorrect (usually lean) mixture can cause misfire/hesitation under load.

If the ignition system does not have the energy to deliver adequate spark under the higher pressure conditions created by WOT operation, the compression pressure can effectively blow out the spark, or prevent the ionization of the air across the plug gap, making an electrical discharge impossible.

If the enrichment mode of the fuel system does not deliver an adequate flow of liquid fuel into the intake air charge when the throttle is opened quickly, the overall mixture will be very lean and not burn properly. Little or no power will be produced.

12° advance may or may not be correct for your engine. There are too many variables to determine the "right" timing setting for any given engine combination. As long as the advance mechanism(s) of the distributor are working properly, the timing should be less of an issue.