nitrous spark plug

Also, using an Air-gap with nitrous, I did the same thing years ago...BUT, keep an eye on ALL of your plugs. I stopped jetting my N2O system up at 180 because I didn't like the difference I was seeing in my plugs from the front of the motor to the back. The distribution was uneven, so I was not comfortable jetting my system up to 250. A simple swap of the intake would have probably cured the distribution problem (going to a single plane like the Victor). Just my 2 cents.