Ok , so you just got yourself a new Holley Throttle Body Injection. Did you know you that you can adjust the fuel pressure at the regulator? This may aid you in tuning the motor when you install it and when you add new parts to the engine. If you are new to the Install, you should know that the Holley TBI will not perform "right" until the engine computer has learned its new parameters.

With the drill bit centered on the brass plug as shown, drill just through the plug but no further. The brass is nice and soft so any drill bit will do.

Thread in the screw into the hole and grasp it using a pair of pliers. Gently pry the screw until the cap pops out.

Notice underneathe the plug is an allen screw that can be turned in or out to adjust the regulator.

The unit has lots of casting flash on it. Before you install it on your Motor, try filing off the flash. Lots of loose flash can be found underneath the TBI which if not removed could end up inside your motor. As a final touch, grab a shop vac and vacumm the flash off. Also use a wet cloth to pick up any extra material left behind.

From my experiances with two Holley TBI's, I have found it nessesary to take off the regulator cap by removing the 4 screws.Reason being? The screw is very seized and may not turn, it may break your allen tool. I used a combination of a mapp gas torch and wd-40. Take a torch and heat the screw on the backside and top, stop then carefully spray wd 40 out of a garden or cleaning plastic bottle sprayer(NOT A WD 40 CAN!)onto the screw top and under. This will unseize the screw. When adjusting the regulator, its best to start turning it counterclockwise or out. This will lower available pressure leaning it out. Turning the screw in will increase line psi and will richen the mixture. Once again I should remind you that the ECM or computer, needs a good 2 weeks to learn the new parameters, so you may want to adjust the regulator after that period for the first time.