What carb would u chose in a 850 cfm,,holley Xp ,quick fuel..brawler

all are good carbs.

It may help to know the application.

Holley makes them all. So, comparing apples to apples....the XP is a race version I believe with mech. secondaries. The brawler and QFT have similar versions available. The brawler is the least expensive. The jetting is perhaps different between them and colors/finishes may not be exactly the same. One may be black/gray, another may have a different metering block color available. Without looking them all up I'm not sure on that.

with no info on your setup like pissing in the wind