I'll just jump in with my opinion..

I think with a 2.50" drop he would rub whether he's turning the wheel and hitting a gutter at the end of a driveway or he just hit's a minor dip in the road... At most I would say 2" drop would be a fair drop to get enough performance out of them without having to worry about the rubbing factor. With a 2" drop, as you probally already know, he'll need a camber kit and with 17's I think that should do him well.

Good luck. :thumbup: