I was traveling home on a long cross country flight and noted at 8500 ft I was only getting about 2500 RPM at full throttle with engined leaned to best power. I looked at my performance chart and it looked like I should be making 2700 rpm???. I took off in 3000 ft denesity altitude. I have a high time Lycoming 0-320 E3D engine in an 1974 Warrior. Cruise speed was about 109-111 knots. Am I missing something or is my power plant showing its age?
