I replaced the main jets with 155s, egts have come up slightly from 900F at full power to around 950. The max rpm remains the same, at the same throttle setting about 3/4 and remains the same through full slide opening. The engine has at most 7 hours on it, including ground running. However it sat for many years in another plane before I started it for the first time in September. With the IvoProp I can adjust all of the pitch out of it and that makes no difference in the max rpm (6000) the engine makes.