I would go with something that doesn't utilize the "butterflies" in the carburetor (like the stock does); those valves really create lots of air turbulence and are no good. I think buying a Raptor 350 carb is a waste of money and time you can get much better...
I would go with a round slide carb (Keihin makes a good one for the warrior they are VERY easy to take apart and because of this jetting is much less of a pain in the ass) - they run about $230.00. Or if you have the extra cash to spend ($390.00) I would
100% reccomend the Edelbrock Qwiksilver carburetor. The Edelbrock design flows much more freely then almost any other carburetor, has a
flat slide, a diesel accelerator pump for instant throttle response,
NO JETTING ever again, has a compressed fuel cell/anti-slosh plate in the bowl for constant fuel delivery all the time, NO choke, Easy to take apart, and gives you an awesome
4 HP increase, and much more - the advantages are superior.
I have owned both the Keihin round slide and I currently own the Edelbrock; I would never trade my Edelbrock away for anything...
Here is the review on the Edelbrock:
http://yfm350.proboards31.com/index.cgi?board=reviews&action=display&thread=1109532460&start=