For those that have used or tried the gobrushless motors. What yhe best method ? i've gotten a prop adapter but it seems much larger yhan the hole in the props. shoud I drill the out ?

Jim,
I've used APC electric props, and I think they are larger than the gobrushless prop shaft (but need to look). You need to use the little plastic prop adapters ACP provides with the electric props. The "precision"  hole is the back hole, whereas the through hole is not always centered. I always ream out the through hole so that if it is offset, it doesn't interfere with the centering provided by the adapter.