To do this is a very simple process.
Buy a Autometer gauge or good brand just as equivalent.
Within the package you will receive the gauge itself with a plastic hard line.
3 You want to route the plastic hard line to the back of the intake manifold(Were the throttle body is connected to). With this you will see a couple of big vacuum lines in the back. You want to to tap into one that read’s vacuum and t off from that. With this running the new t-part to the gauge itself. Make sure you put the line you took off the IM on the t as well.
- Run that hard line back to the gauge routing it through the firewall or your preference. With this the car should read around -25inch of vacuum.
Do at your own risk. Not responsible for anything.