Hello Lake Modified! I'm about 185 miles north of you in Titusville. If you look at my avatar you can see I like the old dirt track style cars, too. My roadster is done in the style of the track roadsters of the late '40s and early '50s. It has a full tubular frame, roll bar with side bars built into the body, twin Kirkey aluminum racing seats, and dual 5-point racing harnesses. The engine is a 4-banger from a Chevy S-10 pickup with a 5-speed manual trans. The whole car weighs 1630 pounds. It's a blast to drive, so yours should be, too. That 300 - six is a torque monster. It would be fun if we could actually get on a dirt track together somewhere, but that's unlikely.
When I started building mine I got the book "Roaring Roadsters" by Don Radbruch. It is a pictorial history of the track roadsters all over the country and a good resource. The main difference between a track roadster and a lakes modified is the location of the fuel tank. Most tracks and sanctioning organizations required the car have a hood and the fuel tank be located inside the body, so track roadsters almost all had at least a hood top and they ran turtle decks (trunks) or shortened and enclosed pickup beds with the tank inside. Lakes modifieds mostly had open rear areas with the tank sitting on the rear of the frame and a hood was optional.
Looking good so far; keep it up. Maybe we'll meet at a cruise-in someday.