Originally Posted by juiced66malibu
Thanks for the reply.
I forgot to mention that I am using Autolite Racing plugs: AR-134 with the cut back ground electrode if that makes any differences.
Also in normal driving the plugs are probably too cold as they foul easily.
I have found those plugs work best with the Nitrous around here. Change to a hotter plug, or try an extended ground plug, and make some adjustments to the gap on test runs.