There is about 65,385 miles on my H3. After changing the spark plugs the startup seems easier, the dreaded dip in RPM's has gone away. I definitely urge you to get it done. The gap for all the plug was at .044 mm. I found it interesting that the part numbers were different although the plugs were both ACDelco. It seems the diode in the spark plug flattened out where as the new ones have a point.

 

i love how gm claims that you don't need to change plugs for 100k. sure, it will still run because the computer will alter the timing and fuel curve as needed, but at what cost? fuel economy and emissions. as soon as i replaced my plugs a noticed a difference in start up, idle, throttle response and power. i also did an oil change, diff fluid change and replaced the air filter at the same time (k&n) and it runs like a new truck.