Gene wrote:

Why fight it? If it is a donor motor.... center punch the head of the
bolt head and carefully drill it out with a drill a few thousandths
smaller than the size of the bolt threads.

Once the head is off... you can probably remove the remainder of the
bolt with a stud extractor, anyway....
--

Id rather not make the donor motor 100% donor motor. It ran the last
time I checked it (a few years ago now) and my goal is to get it up and
running too (why, tho, I'm not sure) on a boat of it's own.