30" long wheel base is to long. It should be 27" because if you buy a body it won't fit your old origional size. The tires are extreme and heavy. the size is ok but you want wider tires and lighter. The motor will work, but you will need to build a main gear reduction and one at the rear wheels total gear reduction should be 30:1. You will have problems with the steering if you want 4x4. The main problem with chain drive is fitting it in a small space and to get the right gear ratio(use 25 pitch chain).You won't be able to make a quick sprocket change to ajdust the trucks speed and power. You will need to make a plate chassis if you want independent wheel suspension