What is this dim of 997 cup wheel centers front and rear?

 

997.1 is 39mm

Same center front and rear.

 

Great, thx... I was think'n they were much deeper. I run 996 GT3R centers and that dim is in the 70mm range.

 

Are they front mounted? The 997.1 centers are rear mounted and have limited brake clearance. To run the larger GrandAm spec Brembos you need different centers. The E88 and newer version the E07 BBS centers measure out in the 52-54mm range from the hub interface to the underside of the of the mounting area (where it would touch the wheel halves). This allows one to change from the Cup rear mounted centers to the larger brake clearance and much lighter E88 or E07 front mounted center without changing the wheel offset.

 

Good point on the barrel mounting surfaces. Yes, the 3R ones have "front/outside" mounted barrels on the centers (top in my pic above).