245's are about 25.5" tall I think. I was planning on trying to keep at least 1" clearance between tire and springs but that may be too conservative? The 205/60's on the rear of mine stick out past the lip on the outer part of the fender about 3/8". If the fender ever got below the tire edge it would definitely cut on the tire. I was thinking of going with a 4" backset as that should give about 1/4" gap between the tire and fender lip and 1 1/4" from tire to spring on that 205, if my measuring was correct of course.
I was thinking about moving up to 15" wheels and the 225/60 (~25.6" tall). Seems like there may be more tire options out there in the 15's vs 14's, at least when I was looking for the 14's.
You running a 4spd or auto and what rear end gears? Let us know how it works out. Be interesting. Good luck. Hope all works out well.