"Gig 601XL Builder" wrote

Now here's the kicker. Just because that certified engine and prop were
mounted and flown in an experimental they can never be considered
certified again.

That is not consistant with what I have read.

If you keep the original data plate on the engine, and do all repair work
and follow all of the directives for the engine, and the work is done by an
A&P, then what you mount it in is not important. When you take it out, if
all work (engine maintenance and rebuilds) as been done up to FAA standards
by or supervised by an A&P, you can indeed put the engine back into a
certified plane. AS far as the prop goes, I am not up with the requirements
on them, but I "believe" the same standards apply for it.
--
Jim in NC