on the second rebuild we had 750 miles on it and would think they would be broke in enough not to smoke. we never tried different heads. parts were federal mogul, melling, felpro gaskets, hasting rings,(iron). no one has told me of any motor using a quart of oil every 100-120 miles on a fresh rebuild. Now I've seen motors with broken rings or pistons smoke alot, but not a fresh rebuild. I've seen people rering motors with just a hone job and they didn't burn that kind of oil until they wear awile and then start to smoke. we had oil dripping out the tail pipes! We have 500 miles on it now and is still smoke free. It must be something with the cylinders, but i'll never know. I'm just glad it doesn't smoke.