Well I hooked up my boost gauge last night. When I rev the engine the gauge goes to the vac side instead of the pressure side. It's a mechanical gauge with the hose and the light power wires. I taped into the vacuum line comming off of the throttle body. Is that the wrong spot to get a reading? If so would the tap be better off of the tree in the back of the manifold? Thanks for the help.

generally your not gonna see any boost while just revving....should be able to get it to hit dead zero but thats about it...if i rev my to 7,000rpms i can read about 1psi...but thats on a good day...

Correct. Unless you use a really small turbo, you're not going to see boost free revving the motor.