labor fees too much? Annual inspection question

[tropical]

As far as the work performed, I don't see a problem with the time billed out for what you described.

Since I don't know the history of your airplane I can't really comment about the second part of the engine not developing power without some more background info. Was the plane producing rated power before you took it in?

And I hold an A&P and IA and also a C337 owner.