For manual brakes I shoot for 93:1 to 95:1 total system ratio for the fronts. then tune in the rears as needed. That is hydraulic ratio multiplied by pedal ratio. Can go over 95:1, but go under 93:1 at your own peril. Below 93 the pedal will rapidly trend towards being rock hard with low line pressure. Above ~100:1 will definitely feel 'mushy.'