Yes, I guess it is. They just will not last very long at full throttle with this fan. Just regular running near peak will get about 10 - 30 runs on the rod. If you are careful, maybe 50 + ?????

I had a header come loose, and loose a little muff. pressure. The engine goes a little lean with a minimum of back pressure. Boy, can you get some vertical for about $180 in parts!