Fabtech's new 4" crossmember systems utilize their proven heavy duty construction and design features for a robust suspension upgrade. The 4" system features high arched lower control arm crossmembers constructed of 1/4" thick steel for maximum strength. The Fabtech ductile iron steering knuckles retain the near stock track width keeping tires under the fender for a clean appearance. Rear lift is accomplished with a block and u bolt configuration. 4in. BASIC SYS W/PERF SHKS 2011-18 GM 2500HD 2WD/4WD TIRE SIZE - 35/13.50R18 WHEEL - 18X9 W/5 3/4" BS W/MINOR TRIMMING; TIRE SIZE - 35/13.50R20 WHEEL - 20X9 W/5 3/4" BS W/MINOR TRIMMING; 14. CAN NOT USE OEM WHEEL AND TIRE.; 60. FITS EXTENDED AND CREW CAB MODELS ONLY.; 55. MUST USE AFTERMARKET 18" WHEELS OR LARGER.
