I used to run modified flatheads back in the mid 80’s in NC. We ran a race at 311 speedway in Madison. 1/2 mile dirt oval. Had around 50 karts. We averaged 95 mph laps! My hands were totally numb from the vibrations at the end of those 20 laps. Fun stuff and you could build a competitive engine for around $1k if you knew what you were doing. Saw one guy that even turned a flat head into an ohv with a home made head. Talk about creativity and innovation. You won’t find that kind of stuff anymore. I’m putting together a LO206 as we speak though. Want to get my son into karting and around here it is by far the cheapest and easiest way to do it. Other option here is TaG. It would cost 2-3X more to get something put together. I see it leaving more in the hands of the driver and chassis set up. Not a bad thing, but miss the smell of methanol and the sound of the pop corn poppers that shook the ground.