The YS91 (110) is a bit heavy but it is a great choice for that plane.
The 91 will turn a 15-8 at close to 9500 , NEVER use full power in a dive unless you do a better job on the horizontal stab than the original. The area near the center on the leading edge will flex and fail at very high speeds . It is not elevator flutter ,the stab can flutter . The LE could be one piece and flying wires wouldn't hurt either . Just a heads up from seeing TWO different planes break the stab in the same place during high speed maneuvers.
NOT saying this is a design flaw . In our quest to brute power these planes it is easy to step outside the design limits . A light 4* 60 will fly with a good 40 two stroker and in years gone by would have been called a 40 size plane ! The YS 91 puts out power much closer to a Saito 120 and will do a fantastic job with that plane . Especially at your elevation.