I have the frpp k springs. 1 inch in front, 1.5 in the back, no problems here. Still on stock 18s polished bullets.you will want to upgrade shocks,struts,and get the gt500 strut mounts, and get an adjustable PanHard bar as well. No reason to have to take stuff apart like this more than once if you can avoid it.
2007 Grabber Orange GT Premium, 5 sp Manual,CDC Sequentials, 18 inch Polished wheels, Corsa Xtremes,FRPP Suspension,BMR Adj. PHB and Brace,Hurst Comp. Plus Billet STS, Steeda UDP's, JLT CAI