Holley/Demon Carb stumble

If I were going to buy Proform metering blocks....... I’d buy whichever ones come installed on the complete carb that uses the body you bought.

I currently have 3 carbs with the IFR in the high position....... but I’ve only run one of them........my built-from-parts HP950.
That carb works fine.

The other two are my built-from-parts HP750, and a BG Silver Claw 750 someone gave to me....... and I haven’t gotten around to trying them.