Having some issues that I have never had before with my '68. Replaced the 20-year old EB 1406 carb with a new exact same model 1406. Set Idle screws settings correctly with Vacuum gage. Engine starts fine and idles relatively smooth. However, when driving her the engine surges in all four gears. I figured it was either vacuum or possibly the electric choke not fully opening once warmed up. Vacuum lines replaced and electric choke reset based on EB recommendations, but the engine still "surges" up and down while driving. Can't figure it out.
Any thoughts would be appreciated.
'68 428 HO M3 Monster, 4-on-the-floor! Need I say more?