I just got in some C5 Thin spoke wheels 17x8.5 58mm fronts(245/45/17) and 18x9.5 65mm backs(275/40/18). I've been reading and came the conclusion that a spacer or adapter will do the job, but I dont know which to get or what size to get, I want an aggressive stance... any ideas on what size i need? I was thinking about an 1" for the back... and will I need a spacer for the front? How big? Thanks!

 

65 mm is too big of a postive offset, you will need to run a spacer anywhere between 15 mm to 27 mm.