Chasing major gremlin, hope this fixes it!

After the first sentence I was thinking MSD box. Very common problem in circle track cars. Most divisions even allow a spare box to be wired up as a back up.

In case you're not aware, FAST now sells boxes for hemis. I believe they are based on the now discontinued boxes from Crane. I have never experienced a failure with FAST or Crane. Great boxes.
OK, ordered another 6Hemi box. Will pick it up before going to the track, and put it in if all the other stuff doesn't fix the problem.