I am trying to tune my 1406 Eldebrock carb. It seems to be stumbling at about 2000 rpm. I can feel it kinda missing slightly. I have replaced the excel pump, fuel pump, floats are ok, Idle just fine. The carb has been sitting for 6 years now and when I first started it it was terrible at any speed. I have disassembled it and cleaned out all jets, fuel passages. This improved the operation but still has a slight stumble at my cruseing speed of 2000.
I have the main metering rod springs and reading the book it stated different colors for different staging vacuums. I am assuming that the staging vacuum means what my manifold pressure is at crusing and under load. At 2000 rpm my vacuum is about 10"hg. With that it would seem I would install the heaviest spring (plain one).
I have done that and it did seem to help but not like it use to be 6 years ago.
My thought was to rejet the main to .100 (it has a .098 now).
Any thoughts from a Eldrebrock fan
Oh yeah, it is on a 350 SBC, headers, cam, roller rockers Edlebrock manifold.