I would look more into the avs2 carb but to me it feels at only offering a 650 or 800 is a big difference and they need a middle man as I think that’s where my engine would be the happiest.
You are way too caught up in CFM ratings. That's a poor way to size a carb.
You need something with a 1.375 venturi and a 1.687 throttle blade.
That just happens to be a 750. You can run a much bigger carb than most on here think and lose nothing if you get the timing curve correct (that's not locked out or all in by 2500...you need a real curve) and then you tune from there. Most lack of bottom end and drivability issues stem from poor cam choices. That's why several of us mentioned the cam.
Many a carb has been blasted from improper timing and a bad cam choice.
