Nice score for what you have in the trade! For what its worth, I'll throw my .02 in on this quad. I used to have a 450r, and my buddy has one now that we're both sharing. When you jet the stock carb, you should be in the mid-180's on the main jet. These carbs take a shorter pilot jet. It looks like the same as the Keihin pilot that we run in our Blasters, but it is in fact shorter in overall length. You'all probably want to swap in a 50 S ('S' for short) pilot jet. The stock 48 is lean for most nodded 450r's. Also, a properly-jetted 450r engine will kick start easily and idle all day long, even with a larger cam, without stalling out. If it idles poorly, the carb's low-speed mixture screw can be adjusted for best results. The screw is in the front of the carb on the underside and is adjustable with a small, stubby flathead screwdriver.
Also, be aware that a later-model FCR carb is NOT a bolt-on swap for early ('04 and '05) 450r's. The 2006 + engines are totally different and you will need to swap in the intake, carb, throttle cable, and airbox from a newer 450r to make the carb a bolt-on. That said, I know you are creative, Wifesblaster, and I'm sure you can make it work.
This thing should rip, but unless you are running a wildly-built engine running on 110, a 60hp Banshee should be more than a match for it. My friend David's 450r IS a race gas quad, complete with 13.5:1 piston, Stage 3 Hotcam, ported head, Sparks exhaust, open air box, etc.... It is very fast up top even fed by its jetted stock carb (blows my ported Blaster away), but it isn't invincible and I think a well-built Shee could catch it.