Iwas just thinking to myself here...the 9-10" of vaccum, was that hot in drive at 850-900, or was that just hot idle in neutral/park? I would expect a 417 with a cam that size to idle in park with at least 14" of vaccum. If there were minor issues like it being lean, or timing slightly off, or carb adjustments, perhaps it woud drop to 10-11 in park. But in gear, something running that poorly would pull like 8-9". If it was healthy in gear, I would be expecting the 10-11" reading at minimum. The cam is just plain mild in a 4" arm engine.