I had my 38’s “taper bored” and completely rebuilt by John, as did a friend of mine. Neither of us have had any problems. I know mine work great. I was surprised how rich I had to go with jetting, but once they were dialed, they’ve been excellent. I also had him put together a linkage and get two 44’s set up to run as duals.
As others have said, his stators are great. I also order o-rings and other odds and ends that he sells. That “ski grease” is great for many applications. Like Darin said, some of it is probably available elsewhere if you know what to order, but John is a good guy and has done all the homework…I just order from him.
I’ve had no experience with his hood seals.