ok i have just got a fully rebuilt 350 holley put on my 4m it had a 350 holley b4 but ran hella rich so i took it to a carbie place and the guy said i have the wroung type of 350 holley on there so he said i'll put the right one on there for $300 and install it for $100
so i went and picked it up and it ran worse than before
(this was with half an exaust so it was loud as fk and didnt want to idle so i got the exaust fixed and brought it back.
the guy said its not getting enough fuel so he put an electric fuel pump on (carter fuel pump - pumps 6psi) it ran better but still had a miss but it wasnt constant it would do it every now and then.
he replaced the plugs, points, condesor, rotorarm and set the timing, he also tried colder spark plugs as it was running rich and said he had put size 58 jets in there from 61 ( jet sizes mean nothing to my feble knowledge)
and still had an intemitent miss
so he said i reckon its the distributer so he suggested electronic ignition
but my wallets getting pretty slim at the moment so i thought id get a second opinion so i rang a performance tuning place they suggested this other carbie place
i told the guy what the go was and strait out he said its the carbie he said its to big he said " the carbie you wouldve had on there before wouldve been single throat the 350 is dual"
he recommends a webber i said i'll bring it in and get him to have a look