I would seriously doubt the guy. He sounds like the type that goes around telling people that his H/C/I fox goes 9's. Its not opinion either, its fact. I dont care if you have a 900hp car, you WILL NOT gain a second in the quarter mile by JUST adjusting the pinion angle. You would be LUCKY to gain a TENTH of a second on your 60' times. And there are ways of proving it, if gaining a second in the quarter was that simple, everyone would know to do that over throwing heads, cams, etc. etc. on their shit.