I have run engine at the weekend,trying verious things,no vacuum leaks present,but vacuum gauge reads 6/7 inches whatever with wipers etc, diss connected,tried advancing/retarding ignition,no good,could it be that the timing gears are out,as i fitted a set from paw and timed the engine striaght up,what would retarding or advancing do,would it increase vacuum either way?please help as this is starting to do my head in!