[Jeff Lee]

Randall,
Anytime something is placed in a bind; either by poorly machined components, inferior components, or improper installation, your performance will suffer. That's why so much $$$ goes into proper engine machining. The more we have the car "in zen" the faster it goes (and lasts longer). I know with my Dana (40 spline) that I've had gears in there for hundreds of passes & when I inspect or change ratios, everything looks as good as when I installed them. I bought a used set of 4.88's from John Dourlet who ran them in his heavy A/S Max Wedge Savoy. John said they had at least 500 runs on them. I put another 150+. Still look great.
I could be leaving .03 or so on the table, not something I'm likely to do in most cases. But I have piece of mind that nothing will go bang when I let the clutch out!