GKTech - 240SX/SKYLINE SOLID REAR SUBFRAME BUSHINGSThe GKTECH 240sx solid subframe bushings are a direct replacement of the standard bushings and ensure that movement of the subframe is kept to a minimum. They eliminate axle tramp whilst also raising the subframe 0. 59" (15mm) which helps to correct the roll center on lowered vehicles. CNC Machined from 6061 T6 aluminum 4 Piece Set Shims to suit GTR models can be seen here: Subframe bush spacer shims (set of 4) FAQS What's involved in installing these