Originally posted by 78 chevy truck its 10 the engine is a 350 bored 60 over the sound goes away when you hit the gas. and there is vacum on the ported sisde on the carb for the hei. it moves the timeing 2 degrees i think
what are the factory settings for the mixture screws arnt they 1 1/2 turn
I could be wrong, but I don't think they are up to 10 yet. Read the numbers off of the air horn. All of the numbers.