Bolted to the frame from front to rear are the alcohol tank (large silver cube), the radiator and fan, the electric hydraulic pump and cylinder to raise and lower the body, a gas tank (smaller red cube) and 2 batteries. Also visible is one of the large rear tires (about 4 feet in diameter). The large disk next to the tire is a huge custom brake rotor, also visible in this shot:
One of the most interesting and unexpected components on this truck, and also one of the best examples of ingenuity and "using the parts on hand", is the rear differential. When you look at the hubs on the rear wheels you find the "Franklin Logger" imprint:
The rear end is actually the planetary differential from a log skidder!
What you get from examining a vehicle like this is a sense of the knowledge and skill of the creator. Think how much the person has to know about all of the different components, and then the skill required to bolt and weld them together into a working vehicle. It is truly an accomplishment!
One of the most amazing things about modern society is the sub-societies hidden within it. Tractor pulling is a good example of this phenomena - every permutation you can imagine from customized lawn tractors to Bigfoot make up the spectrum, and there are thousands of fans in each niche. If you are interested in learning more about tractor pulling, the following links will get you started: