I did the same thing on the last modifications, I just didn't photograph it. I also filed off the bottom edge of the cylinder on the ouside surface of course. You can visualize how airflow is going to be inside something like we do on the outside of airplanes. I am trying to get over 8k with this engine. I also have a Walbro 047 WT 324 carb on a single bbl engine ready to test run. I describe this 5/8" bore carb elsewhere. We don't know what the limit is, unless we push it. I think the 1 bbl has potential. How about a special intake/carb/spacer/manifold for the 2 bbl carb to try on the 1 bbl engine? I also think I can design a low profile intake manifold for the 2 bbl carb to replace the 2 -story original intake which limits how large you can go on the 2 bbl intake port. I would still use the Reed intake tubes, if the current engine runs as well as I think. There is no end to what we can come up with, is there?