Well, that would depend. If you can borrow a carb, you absolutely should try more CFM. As for buying carbs to test, not unless you're made of money.

My 500" wedge gained just over 1 mph in the 1/8 going from a 950 to a 1050 Dominator. I don't remember exactly what my gain was when I went from an 850 to the 950. But it seems like a mile an hour or so.

How big a carb, type of spacer (if any), type of boosters, etc. are best determined through testing.