Hi Steve , is the car running in stratified mode when it should not be as 3 hg vacuum could suggest this, as throttle body is activated to give no vacuumm in statified mode. Could the timming still be incorrect ie crank pulley woodruff key broken.Massive air leak but i dont think this is the case with cylinder head being removed & refitted and this would of probably would of being discoverd when this was done.Just some thoughts Darren