First I would like to thank all of you for the responses that you have posted.

They have been gapped at .035 and that is how they will be installed.

SR-24 - It will not hurt my feelings if it cleans things uo a little. The HP 500 carb engines are set up on the rich side from the factory at least in my opinion. Rich is safer than lean even though less power. From what I understand they, by design heat up to the correct range faster than a regular plug and also run cooler a high RPM. The extended tip does in efect to a minimal degree have the same effect as an increase in timming due to the tip being farther into the cylinder and A/F mixture. The factory timing setting of 34* is also a little conservative just like the carb jetting.

CPQTIM - It is my understanding that the Rapid Fire # 1 is the correct crossover in regards to being the correct heat range. I feel that the heat ranges are the same for both plugs.

FloridaSon - How long were yours installed before your miss came back? I am embarrassed to tell how many hours I have on the plugs I am replaceing and still do not have any detectable high speed miss.

OBNOXUS - I feel that if your jetting was alright to begin with a plug change alone will not cause you any problems unless you were to go to a much hotter heat rang plug.

Thanks Again & Be Safe,
Mark