I didn't realize the Duratec had a different pattern from the Lima, but yes - the M5OD has been cast in several patterns to accomodate the different engine familes. One for the 2.9, one for the 4.0 (which is actually the same bolt pattern, but the gear ratios are different and the outside of the casting is visually different), one for the 3.0 Vulcan motors, one for the Lima 2.3/2.5's, and apparently one for the Duratec's as well.