Originally Posted by seafoam56
i notice that my engine has a miss in it...i watch the tach as it idles at 600rpms i notice it dips to like 550 every few rotations...could this be an ignition issue...its kinda like a miss fire....you can hear it in the exhaust...or could this be a carb/gas problem...open for thoughts.
I wouldn't worry much about an idle miss if it goes away as soon as the revs pick up. Fuel distribution at idle is never very good with a carb, and this being a 400 horse 350 it's pulling some cam and has a somewhat over-sized carb. This is recipe for an idle miss, especially if combined with an unheated or single plane intake manifold. Probably the easiest solution is to speed it up a little bit.