Originally Posted by houston

tip: if you are trying to use a plug for a gallon you are seriously jeopardizing your engines internals (its not a "my plug lasted 2 gallons" contest) , plug filaments get very brittle , they are designed to, so as they heat up to pretty high temps and are subjected to high pressures being part of the combustion chamber . i would highly recommend utilizing cool plugs no more than half gallon and hot plugs no more than 1/4 gallon of fuel , leaving hsn just a touch on the rich side will keep plug cooler as noted by the "wet" plug when inspected .you will notice the tune fluctuating , sign plug needs to be replaced for optimal performance

i have personally not have had any problems with the c6tgc as of late but dont really recommend 97t except for break in plug as they are very very brittle , large air orifice and thin element provide for easy tuning but plugs dont last long at all , i would personally change 97t plugs about every 6-8 tanks of fuel (no joke)

take my advice for what its worth , its up to you , i am not really trying to sell anybody plugs as some have mentioned before but more so offering the advice based off of knowledge from what i have seen from customers engines and have personal experience with