As far as the rear of the body loose, there is only about 14 inches of bed behind the body and, after a lot of miles had no problems. I am not a fan of the expanding plug body attaching mechanism that TP uses. I drilled the threads out of the 4 plugs, then drilled thru the frame and made a solid thru bolt attachment, using the body of the plug as an insulator. If as Mickey says, the body is more tightly fastened, stress cracks WILL occur. The frame is fairly flexible - remember, the engine actually acts as an active cross member and that it as well as the trans are rubber mounted. While many of TP components are well engineered, and will take a h@#% of lot of abuse, it was still designed for a Chevy 350/350 combination of 250 to 300 +/- Hp. When you change those parameters (i.e. more horsepower or weight) you may have to reinforce pieces. As far as the Speedway chassis, as a personal preference I do not care much for buggy sprung cars, but they do work.

Oh, as far as driver size, I'm 6'4" and over 200#. And yes, my knees did stick up above the sides, but in reality, with the top on, didn't look TOO funny. I never had a problem with leg room, but you sure shouldn't wear anything but sneakers for foot room.