HPI 87602 Wheely King 4wd Conversion by HPI Racing Trick out your Wheely King 2WD with full-time four-wheel drive for extra traction and grip. This conversion kit makes it easy, no searching for individual parts needed to make your Wheely King into a 4WD monster - everything needed is included! HPI Racing conversion kit adds four-wheel drive for extra traction and grip. Individual parts needed to make your Wheely King into a 4WD monster truck. Requires: Installing co