I saw a toyota powered rat rod, In N calif a while back Take a class and learn to weld. Harbor freight sells a tubing notcher on sale for $50. use hole saws and plenty of coolant and you can build your roll cage and stiffen up the chassis.My old buddy, the late Joe Davis built one of the first funny car mustang's. just the skin over an altered chassis.. his picts are still in Half Moon
Bay Calif .. at one time he had 4 records drag racing. It's best not to drill extra holes in your cage. if you do, you need to drill enough to install grommets so the wires don't get chafed and wear thru the insulation. MY brother built an old dirt track car, the body was basically just the skin with tubing braces and brackets to bolt it on the floor , seats, inst panel steering and pedals stayed on the chassis. you could drive it that way