Actually mine was a 996 shifter and yes is was a bit wide but i made it fit. I had a 996 GT3
cup car box first.It now has a 997GT3 with the original shifter. The detent to reverse does take a little effort but I got used to it. and the resistance helps not to select reverse when you really don't want it. I did find the cable adjustment was finicky, it took a few times to get it just right. That could be a good place to start. There is the correct Porsche tool to adjust the cables, which after much pleading and begging I borrowed from a local dealer.
But after a couple of attempts I got the hang of it without the tool.