Before removing screws use a dremmel tool to grind the threaded end off. These screws are usually mushroomed over and if you don’t take care, they will break.
Install the throttle valves with the trademark ‘C’, inside the small circle, facing the direction shown. Loosely install new attaching screws, then close the valves so they seat properly in the bores. That means no gaps. Tighten the screws securely. Use blue locktite on the screws so they don’t come loose and fall into the manifold. You can also mushroom the threaded end of the screw.
