4500lbs is pretty optomistic. I corner weighted mine on electronic scales. With a 1/2 tank of fuel and me in the seat I weighed 4910lbs. There is quite a bit of weight that can be removed. How about a narrowed 9", 4-link, and tubbed for the back? That 9.75" if huge. Leaf springs way to heavy. Wheels and tires are huge for weight savings. Cage will add some weight but the offset of firming up the chassis is well worth it.