First I verified that I was 0deg before the twist.
I used the 2x4 to twist the angle. I must admit I checked about a hundred times to make sure that I was twisting the right way, the top of the angle bends in, and the bottom bends out. It only takes a few mins to get the 17deg bend.
So glad to be finished with the longerons. They got stored up in the garage for installation later.