I think vacuum is what pulls the valve open. At least on my 2650 (which I know isn't an apples-to-apples comparison), when the engine isn't running, the valve is shut, and there is a good deal of pressure pushing the bypass closed. However, when the engine is idling, the bypass is open.
So I'd probably try to carefully align it to where it was exerting pressure, engine "OFF", and make sure it's opening, engine "ON". I'd also make necessary finite adjustments with the bypass screw.
Or upgrade to 2650
See if you can align the bracket to the witness marks left by the original fasteners. Usually - bolts leave friction marks after you remove them. Maybe aligning the bracket to where it puts the witness marks under the bolt heads will get you close.