WIth 997 wheels you can run et65 10" wide wheels up front, and 11" in the rear.

 

Four Cup II replicas were cut in two on lathe. Two pieces were welded together in jig after above pics were taken. Two pieces were some mm's on top of each other when they were welded. After this, seams were cleaned up. In balancing machine they do not show any meaningful throw or unbalance. Once painted, its virtually impossible to say anything was done. Other wheels done in similar way have endured many years of drag races without any problems. Still, I would not do it myself.

 

What size tires?
I ran 275's on 9.5" w/ 73mm and it just cleared on a lowered car.