Red Neck Smoke test -
1) Remove air filter.
2) Wrap the air filter with glad wrap.
3) Put Air filter back in, the idea is to block all air going into the intake.
4) Remove the brake booster vacuum hose.
5) Light up a Black & Mild cigar, and blow smoke into the brake booster vacuum hose.
6) Plug vacuum hose with thumb, repeat smoke, and look for smoke leaks.
7) Any were you see smoke, you got a vacuum leak.