I just installed a new set of Champion rj12yc spark plugs which I have been using for years and THREE are fouled out.Is there a better plug for a hot 383?Here's the combo:
.030 12.5-1 trw dome(heavy slugs)
free floating pins
zero deck block
906 78cc heads(bowl blended)
6-barrel setup(promax base plates)
509,soon to be racer brown sth-42 cam
msd ign.
4-speed
4.10-1 gear