I finally was able to have some time to test my change to the ram air duct. I am very pleased with the changes. I flew for 1.7 hours and at cruse the cylinder temps were great. The max tem on #5 cylinder was 317 at clime out to 6500' at cruse 260 F at 2800 rpm and 6500' with out side temp of 59 F, I have the wood prop on right now so cruse at 2800 rpm was 93 MPH. I am waiting for my spinner for the Whirlwind prop. I have 37 hours on the engine now and am ready for some longer flights. I will update more.