I'd say it depends on the shape of the combustion chamber and the amount of quench. We don't know what the build is so we can't really tell if there is a danger of failure. I think 200 should be ok with 93 octane but about five pounds lower with every one point drop in octane. Fuel quality is another problem. Premium gas where I live will hardly keep the engine running as its so old. It cost so much no one buys it and it's now junk. I run 120-125 cranking psi. but I also have aluminium heads and a heart shaped combustion chamber,zero deck with lots of quench. Like Firebob and Bigchief, I would want the best gas I can get without knowing whats inside your motor. Better safe than sorry
