ET'S with ported J/or other iron heads SB

No, w2’s are not allowed. As for tech, the person at the event who organizes that days racing would do tech, you could be asked to pull a valve cover or remove the carb. Looking for the stock casting number. Small blocks can run x heads or any of the other u/j etc. same for the intakes and exhaust manifolds. Other than starting with the correct castings and maintaining their outer stock appearance. There is not a bunch of “specs”. Could you spend an obscene amount of money and have someone cast a 340 intake in aluminum with all the casting numbers on it and paint it in magnetic paint sure, are you cheating? Yep. Is it worth it for a trophy? Not to me. I’m never going to win an event, but I’m almost guaranteed to get a couple of close races during a weekend. My efforts at weight loss stop at “it has to be bolt on”

Or you could run a factory cast iron 4bbl manifold