RE: Goldberg Extra 300
Dobra
15% will not hurt your OS straight out of the box. You'll pick up a couple hundred RPMS and it will idle smoother.
Is you'r OS a 91? If it is, I wonder if a 15X8 is a bit much(for break-in).
What's the recommended break-in prop? I think my Magnum 91 4banger was a 14X6 or 8.
-Me