I guess.

I have been running a MSD distributor and 6AL box for 15 years and have never had this problem. I have built 7 or so big block Mopars in the past 11 years all with MSD ignition systems and can’t recall any such problems. I did have one OTB failure on a digital MSD box but that’s about it. 4 of those builds all ran the same MSD 6AL at Pierce Engineering in Lansing on the dyno. At this point I would get rid of your ice ingnition box and get a MSD box or borrow one and see if that it the fix.