There is a way of doing it Jerry, I believe a vacuum gauge can be installed, if I'm correct, the vacuum should be unusually low. I usually just do the simple test I've outlined, it gives alot more positive results. Just loosen all the bolts attaching the pipe to the manifold, no need to remove anything completely. Never had a problem just doing this as a test. In the unlikely event you would be stopped, I'm sure most officers will understand. Don't do it at 3 am obviously, and I would assume you would know within a mile or two if the problem is gone, then cork it back up until you can fix it. You'll feel alot better doing it this way rather than hoping that you are analyzing the test results properly, this will be a very expensive repair.