Mate I could talk to you all day about this subject as I have had loads of greif with coil overs and drive shafts.
What year is your car?
What coil overs are you gonna get? (how much?)
What wheels do you have- &tyre size.
I put longer sierra ones in, but then had to get them cut down and a groove cut in at the diff end driver side- nice to do on hardened drive shafts. My car is well to low- see Performance ford Dec 2003 P118 the bottom left is with coil voers raised, the right one is with them lowered!! The biggest problem I get is gaiters at £15 each (4) keep splitting as the driveshafts point up. I suggest you ring us on 01702 482545 9-6 mon-fri Ask for Chris. We'll talk.