My Evo 46 turns 300 more RPMS than my other 46 engines on the same prop and fuel ( ST45-OS46SF ASP46 )
These engines are overlooked and cheep to aquire
I have an EVO 53 that has great power bought it new real cheep
They have true chrome linners
i am sure the 91 will be a good performer from my experience with other engines in the brand
Not sure how they would hold up for the long run as that is the true test of the great engines but with a true chrome linner they should hold up real well

Enjoy