Brad,
How tight was your serpentine belt? the reason I ask, is I have seen cases where a mustang guy will really tighten down the drive belt for a S/C and it will flex the crank a bit. A crank w/ extra vertical load on it would be far more susceptible to failure under oil starvation.
In other words, I think oil starve is you problem, but the load on the crank from driving the supercharger helped it go boom faster.
Personally, I say go find a wrecked taurus, smooth down the pistons for a lower CR and toss in the 3L. at this point it can't be any more trouble than a new 2.5L
