Has any one ever attempted to remove the threaded ports in the cyl heads ? I was thinking it may be the source of a vacuum leak . After going thru my carburetors and installing new rubber tubes on both sides of my carburetor's .My air bleeds are only adjusted out about 1/16 of a turn . Carbs are have been synchronized with 8" of vacuum at each one . The idle is at 1,100 rpm's