Awesome project! Great workmanship! On page 13, the photo of such a long chassis on the ground (driveway) makes me wonder whether in fact there will be sufficient clearance to allow for flex, suspension travel, and minor irregularities in the racing surface (i.e., salt). You might want to check all that, bearing in mind that the final weight will be substantially greater than what you now have. Additionally, aerodynamics might conceivably create some downforce that tends to lower the central part of the entire chassis.
If some of the body (sheemetal, for example?) is below the lowest frame tube, that crowds the ground even more. Scraping the ground during a run isn't likely to help you achieve your goal. Best wishes.
tallguy