http://alliantpower.com/sites/allia...a/technical-bulletin/2009/aptb_01-09r1_en.pdf
this document shows motorcraft quality and spool valve groove
http://www.powerstrokediesel.com/docs/Injector Comparison.pdf
Did you get the archoil put in?
Mike - interesting idea, and I like it. I may go one step further and send in 3 samples, just for grins.
Sample 1 - oil with 5k miles on it, no additives (oil I'm changing today)
Sample 2 - oil with <1,000 miles with Archoil 2300
Sample 3 - same oil as Sample 2, but at 5,000 miles
All samples would be Valvoline Premium Blue Extreme 5w-40.