You can go in at 108 if you want, but it will be technically 4* retarded from where Cam Motion wants it. 108 will shift the torque curve up.
As a general rule, Cam Motion usually calls out a 4* advance from LSA. Usually. I had one cam ground on a 109 that went in at 109 but it was a weird combo. 104 will probably be better for what you want.