FBO's black HEI ignition box

Re the discussion of spark gap, my 1996 Plymouth 2.4L would misfire bad when going full throttle at low speed, like accelerating on an on-ramp. If I backed off the throttle slightly, the engine would smooth. Of course, that could be from poor fuel flow, but I suspected spark since it didn't misfire at high rpm and wide throttle, like climbing the Sierras at 65 mph, which is higher fuel flow (i.e. power). I found a TSB for the same engine w/ turbocharger, which suggested lowering the spark plug gap. I did from spec 60 mil to 50 mil and no more misfires. Why the misfires at above conditions?

At low rpm there is less pressure drop in the intake manifold. With open throttle, cylinder pressure is at max (close to atmospheric). Of course even higher with boost (TSB). It is harder to throw a spark at high pressure. In the reverse of a vacuum chamber, sparks can easily jump many feet (air is easily ionized). Why did it affect my engine? The vehicle had suffered a left-front collision (wifey driving) which knocked the front end over (bent strut) and dislodged the PCM so perhaps slight damage to the ignition circuit (cracked trace on board?), or perhaps just degradation with age. Anyway, runs fine with 50 mil gap, which is still much more than the 35 mil of old Mopars.

BTW, last year daughter pulled in front of a Ford Transit mail-van which hit the right front (bent strut and tie-rod). While that adds symmetry, I had already bent the front back after the first hit. The Transit was totaled (wimpy Ford full-size van vs Mopar minivan). I fixed-er again w/ new strut ($20) and fender & door from junkyard ($150), then painted currently popular light-grey so daughter won't fuss about the failed clearcoat (shiny is all she cares). The paint was leftover from painting my 1985 M-B after daughter crashed it (2 crashes in first 2 years driving).