Hi there. I am trying to improve vacuum as part of a smog failure and can't get above 16# and am chasing potential leaks. I have been spraying carb cleaner and the only place that drives up the RPM's or causes vacuum to increase is the manifold fitting that provides vacuum to the brake booster. See pic below. As a troubleshooting step, even though the brake booster hose and the AC idle adjust vsv hose seemed to be in decent shape, I took an inch or so off of both to be sure. No change in vacuum or RPM's with the hoses reseated. This makes me think the fitting is leaking where it screws into the manifold. Is this a normal failure point?