The higher the ratio, the more likely you are to encounter some whine in an 8.8. Setup is much more finicky as the ratio gets wider. The way the factory assembles them with slap to torque can be a little hit or miss.
If it's not too terrible, you might be better served with louder exhaust because opening up the rear can cause more problems than it solves. Ford won't do much unless it's quite severe, even on a new car.
2014 Premium GT, SGM, Brembo, Auto, Tech, Comfort, etc. GT500s, Steeda UCA, VMP auto tune, 100 shot on BBR tune, best et: 11.38 at 120.85
2012 GT, Candy Red, Brembo, 3.73, Tech, Comfort, etc. Procal tune, Roush upper, UMI LCAs, Steeda red bracket, GT500s, 28X10X16 Hoosier slicks, best et: 11.91 at 115.23 RIP