The two best Shark setups I've seen were, from the late Jim Armour and his 54 oz ST 60 powered Shark. I launched that plane for Jim several times, and I can tell you the plane accelerated like a rocket. It was actually uncomfortable to hold it on launch-it had so much power.
The next was; Dave Sabon and his PA 65 side exhaust powered Shark. That plane was off the hook!! Dave took a semi truckload full of trophies in Socal with that ship. With the right power, there is absolutely no reason you can’t compete in Expert with a well- built Shark.
The Shark that I got a chance to fly, had a ST 56 in it and that was PLENTY of power. My shoulder was sore after the flight.