Interesting, thanks for your input! As I hope I mentioned, I'm still rather new to this so I'm learning as I go. Part of the reason I was leaning towards Wiseco was availability, the Yamaha pistons are becoming hard to get and costly, as well as the rings. Luckily, the one from Engine 2 looks pretty good. Maybe I can keep using that. The piston from Engine 1 is trashed, heavily scored along the side. The reason I am going to use a block off plate is simply so I can get it running first. I have two oil injection rebuild kits, so I will rebuild both oil pumps and then install them. That way I can verify the oil pumps are working, after I'm already sure the rest of the engine and bike is good to go. I believe the service manual has the volume of oil that should be pushed by the pump at certain throttle positions, so I can verify that way. Right now, I am using the Yamaha factory service manual which I have been pretty happy with. I'll look into the Intertec one, thanks!