I am 6'2" with a 31/32" inseam (jeans, sorry i dont know the exact biking inseam). i ride a 2005 Trek 1200 that is a 56cm frame which is definately on the low end of our comfort range. ideally, i should be on a 58cm but the deal was too good to pass up. my stem is at a 45 degree angle and that helps with my reach a bit.
It would seem that you riding a 63cm frame would be enormous to the point where you couldn't even reach the ground. doesn't seem that safe.
hope this helps