If it's a 2 pole 3660 motor like a feigao, it probably won't survive depending on it's Kv. Those type of motors generally only stay cool if kept under 35k rpm, 2350kv on 6s is probably going to heat up pretty quick. A heatsink with fan and keeping the speed under 45mph will help, but I'd keep a close eye on temps if you're going to try it. And if you're new motor is going to be a 3674 2 pole run on 6s I'd get a Kv of 1700 or less to keep the Rpms and temps down. You can always slap a bigger pinion on it if everything is within safe limits.
http://scriptasylum.com/rc_speed/top_speed.html is the link to the speed calculator, you can play with different Kv, voltage, and gearing to figure out speed and Rpms. Check out the rest of the site for other help deciding on motor size and Kv as well.