So I wiggled my hall sender plug at the distributor (per some advice)
and it had a good bit of free play.  The plug looked good, so I wasn't
expecting much but the problem that I have been having with the
backfiring didn't come back.  Hmm... I was only able to drive it about
15 mins but before it would only go about 5 before it started
backfiring.  Any advice on how to fix the problem for good?  Do I need a
new distributor, or is there a replacement plug made.

-Nate