OK - Think I got it..When I replaced the coil pack, the truck was a little
better, but still hesitating/mis-firing badly.  Since the code was a 303, I
pulled the #3 plug to see if it was perhaps fouled up from driving that long
with the bad coil pack and misfire.  First, when I went to pull the wire
off, it didn't feel like it was on right.  Then, when I went to pull the
plug, I thought I wasn't getting the spark plug socket fully on the plug
right because it turned too easy.  Turns out it was, and that the plug was
not completely tight!  Then pulled the #1 (because it's easy and right
there) to compare the plugs.  The #3 had a light brown (almost rusty color)
on it, but otherwise looked OK.  Inspected the #3 boot to see if there was
any blackening, but it looked brand new still.  The #1 Plug looked like it
should for a slightly used plug - Dark from firing, but not oily.  Lightly
cleaned both plugs with wire brush, but swapped the plugs when reinstalling
them.  I torqued them both down and put the wires back on making sure they
were fully on.  Truck runs great again after test drive.. I know nobody
replied, but maybe if someone googles with the same issue, they may find
this answer to a poster's own question and check to make sure to check the
obvious first before thinking the worst.  I'm humbled and learned a lesson.I
guess it's possible I could have gotten distracted or something and didn't
torque the plug or fully seat the boot correctly when I changed the wires or
plug a while back.  Just because you do the work yourself doesn't mean your
perfect and can't make a stupid mistake... :)

IYM