IMO you should forget you ever heard the word Proform, it's nothing more than a Chinese copy of an old BG Claw design.
In order to make the main body work you need to change the base plate and metering blocks by the time you get done you'll have a Chinese carb with Holley float bowls, no warranty from anyone and no tech support if you get into trouble.
Look into a Mighty Demon, designed without an air horn, better air entry, full tech support, American Made, you just can't beat them.
http://www.4secondsflat.com/mdemon.jpg