HOLLEY HP, XP

probably for the end of the year, I would go and ask Santa Claus, for a new carburetor for my 1970 Dart with 440RB engine.
the Holley HP carburettors I have already used several times in my work with great satisfaction, (IsoGriffo 327 V8 chevy), (Jaguar 4.2).
I do not understand the technical difference of the XP model in relation to the HP model.
thanks for any help you can.

I would buy something other than a Holley. BLP, FST, call William Baldwin (you can google him or look him up on Facebook), Thumpr carbs on Facebook, Mark Whitener...I think he goes by Lightning Carbs...even a ProForm.

I’m not impressed by the Holley series of stuff. You can get more for less with something else.