What Casey said.
That FAQ article hasn't been updated since 2001, so it's only for the 4R100 tranny behind the 7.3L PSD. Works great for that. /ubbthreads/images/graemlins/warmsmile.gif
But a TorqShift requires a different ATF. It uses only MERCON SP ATF. Not the plain ole MERCON used by the 4R100. Plus you have a remote tranny filter we don't have, so be sure to get a new filter element for that.
In addition, the cooler bypass valve that returns ATF from the torque converter to the tranny - instead of sending the ATF through the coolers - opens at around 165º F. In other words, the ATF bypasses the coolers unless the ATF is hot. So that means the same basic ATF-change procedures should work, with two big differences.
1) The tranny must be more than warm before you begin. The TorqShift runs hotter than our 4R100s, but 165º requires some work to get it up there. If you don't begin with a hot tranny, then you're going to have a lot of ATF coming out the wrong place and making a big mess on the driveway. Plus any ATF you waste on the driveway will be the new stuff - not the old ATF you're trying to flush out.
2) The first 13 quarts of new ATF (7 the first cycle + 6 the second cycle) must be heated on the stove (or somehow) to get it up over 170º or so before you pour it in. So that means a big 8-quart saucepan or stew pot plus a funnel that will let you pour hot ATF from the saucepan into the tranny (without getting scalded). If your better half would have a conniption fit because you used her good stew pot to heat up "oil", then buy a cheap one to use just for heating ATF. /ubbthreads/images/graemlins/wink.gif
After you button it up, that last 7 quarts can be room temp when you pour it in.