a can of starting fluid. Spray small bursts around vacuum hoses and listen to the engine. Dont go crazy with the fluid, just a spray here and a spray there. When you hit the area where the vacuum leak is the engine will ingest the fluid and the rpms will pick up. I'm not sure what your na is equipped with but it shouldn't be that hard to locate the leak. Try listening closely for a hissing noise and maybe you can locate it without the fluid. Stick your hand in there and slightly wiggle on the vacuum hoses routed around the rear of the plenum and see if you can find it. Good Luck