Murph, if she's proped right you should be seeing pretty close to 2mpg. Too many prop those 150 Eagles too high. Those engines put out their best power proped to turn 52-5300.. The 175's to can twist out to 56-5700, but the 150's do better 4-500rpm lower.
We can check this when I look at her in March.. I'd really like to see the props you have along with engine heights..?