Hi SRT8... I know you are looking for best 1/4 times for a MKS, but nobody seemed to have answered to your question. I own a SHO, but my wife's DD is a Lincoln MKT. With only a Livernois tune, I ran a 13.3 at 103+mph... So, with a Livernois tune, under same conditions (DA around 0), a MKS should be able to run high 12's definitely.
Cheers!