I don’t know if I had the same type alternator bracket, but I ran an Edelbrock intake/long water pump setup years ago when I first put my truck together. Looking at an old photo, as best I remember I just modified the bolt hole in the bracket into a slot by cutting out the center of the bracket hole. Rather than a circle it ended up a U shape, allowing fore and aft adjustment. I clamped it with a washer large enough to cover the gap and it worked fine for many years until I installed A/C and swapped to Alan Grove brackets.
