Thanks everyone for the advice, it is great to hear what has worked for other people. There hasn't been much responce to this post and then all of a sudden it took off.[X(] I have decied not to put smoke in the plane but I am still looking at using a pitts style muffler, any thought on this? I had hoped to have the plane in the air by now but budget restraints on purchasing the engine and damnaging my Extra 300 have delayed progress on the Ultimate. Please keep the posts comming.