According to Yancey, the "originals" were replaced after the first flight. He also said the "originals" weren't very original...
I know they wasted a crank in the right hand engine on the first flight, the crank was in a glass case at the hangar. I'm sure the valves, valve springs, pistons, rings, etc., and a lot of other normally replaced parts were replaced. For what I was told they paid for each engine to be rebuilt, I'd hope so. They pulled the right hand engine out after the first flight, and sent it back (maybe they sent both of them back, I would have), and had a new crank put in it, and a couple of rods I think, from what I saw of the parts. I saw it fly at the last show they had at Middlesboro, and both Steve and Bob told me those were still the original engines. If they still had the original heads and blocks, that'd be considered "original" by most standards. At least by most restoration standards.