Thanks guys. I did some research and it appears the bushings are standard 1/4 20 threads
As for the brace, right now I'm at 7.5" with a 1/2' nock height.
The bow is reading 53.5# at my 29". I put a thicker strike plate on and it appears my arrow is right on center cut.
My current arrows are Easton ST Excel 400s cut to 30.5" with a standard 17~18 grain aluminum insert. I've tried point weight from 145 grains up to 250 grains.
The arrows fly really fast and it's sometimes hard to see, but I think I keep seeing a barrel roll...I'm a right handed shooter and the arrows appear to kick out left before returning to center. My accuracy is good, but the flight leaves a lot to be desired.
I'm wondering if I need to go to a stiffer spine, maybe 340s.