Easy test for a vacuum leak, with an air cleaner installed that has a single snorkel, lightly begin to take your hand and cover the inlet, slooooooowly....

As you begine to close more and more of the intake snorkel off, the engine may increase RPM.

If it does increase, 100% thats a vacuum leak...

You can use a rag as well to cover it, be careful, dont hurt yourself....

I used to care but....... things have changed