I have to say I'm skeptical about the report of an OPS60 in a 10 size Shrike. It won't fit and the logistics are not there, someone is pulling someones leg.
That said a little bit on the Norvel 074 conversion. It's an easy fix for a little more speed but there is a penalty. Todays logic seems to be bigger motor, go faster, simple. It really isn't that simple if you really want to go fast. To start with carbs are a hinderance in a fast plane so you only need a venturi and a shut off. A pressurized system to feed the critter and above all a motor that is designed to deliver the goods If you want to really go fast with this plane get a Nova Rossi 09. Then there is the matter of the right fuel,prop and above all the piloting skill to fly the thing safely.
Of course that is a rant and if all you want to do is go a little faster then by all means do the Norvel 074 but to realize any blood curdeling adrenalin pumping, heart stopping excitement be prepared to be a little disappointed.
Dennis