Today I put the groove on my uncles 98 Chevy. This is his work truck it has 247,000 miles on it and he commutes easily 100 miles one way. The truck had a slight miss while idling. I was actually surprised when I pulled a vacuum and it had 17" to start with. I removed the throttle body and cut the groove, I also cut a new gasket to reduce idle airway flow, next I capped the PCV and last was able to get a vacuum of 20" afterwards. Before I started I had him smell his exhaust and it was not very pleasant. We took a test drive and right away he was amazed with the power, he told me he thought that engine would never run like that again with that kind of mileage. He noticed 0 - 60 was much faster and smoother, the RPM's were lower cruising at 55MPH, also the engine temperature gauge dropped lower than normal. He kept saying I am barely holding the pedal and we were holding 55 - 60MPH. When we finished the test drive I had him go back to the exhaust and he was blown away he could not smell anything. He will update me with mileage gains and I will post them here soon. Thank you.
