Maybe I'm crazy, but I think high performance Fords need to be beaten in, not broke in.
Of the SVT/GT's I've owned, the ones that gave the most troubles the soonest were babied like I wanted to keep 'em forever. But now I have to ask myself, "why bother? they ain't worth 2 nickels at the end of an extended warranty anyway".
The Tremec in these is going to give troubles or not, no matter what you do. Luck o' the draw. I think the stock 4.6 is pretty solid.
IMO, you should warm it up good and run the p|ss out of it whenever you have a chance. Of course... within reason. Going sideways across a bridge or swinging @ssbackwards into the opposite lane can cause traffic problems.