Wow im suprrised you got that much of a gain. I didnt get anything like that in fact it didnt seem to make a difference at all. I dont think i raised the exhaust roof anywhere near the .110. It just didnt take that much to get it from 140 deg to 150 degree. I didnt do the eliptical port but stayed mainly with the original port shape. Did you remove the center bar? Its hard to tell as im having such trouble with my test equipment and am not gona make any more tests till my new tach gets here. I have some more cylinders so i should be able to do side by side performance comparisons. Thats a good idea on taking the average of three testing points. One thing that seems to be common on these engines is they lose a couple hundred rpm after running full speed a while and get hot. after cooling at idle and run back up it will produse the same results time and time over. I try to take my readings after it gets hot and the numbers stabilize.