It's great to say that I know the person personally behind this wonderful part number in the O'reilly system, I actually went to high school with him.
He is a major BTTF fan and works for the Marketing and Design in the Corporate Offices in Springfield, MO
The 121G part number started out as an example that was used when they put on a training seminar for the Managers Conference and as you can tell, it caught on well!
It also helps that I work for O'reilly part time on the weekends so I have made some inquiries when asked about this!!!
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Ecomodders try not to do 88MPH, but collectively probably know how to fool it to energize at half the speed of a perfect 44MPH!!!