I believe it is a myth that stretched spans provide more revs.
Except for a few with remarkably flexible hands stretched spans lead to injuries down the road.
I use a relaxed finger tip fit and while not a high rev player I have been measured at about 300 revs. The relaxed fit gives you more variables to be used in your release.
Most all of the tour players I have known have relaxed finger tip fits. Chris Barnes, Rick Steelsmith, Justin Hromek, and others from Wichita State all used relaxed finger tip fits.
Assuming you are experiencing reduced revolutions with the new grip.
With out seeing your old span it is hard to say if they shortened a stretched span or a span that was already somewhat relaxed. If your span went to short then that could be a part of the issue.
I would also look into your thumb pitch. Thumb pitches can dramatically alter when and how you release the ball and how relaxed you can keep your hand.
A shorter span often will allow you to use less reverse pitch in the thumb as well. If he kept your old pitch in the thumb you maybe releasing the ball too early.
