I would seperate the parts into complete motors, and sell them "as is"... one at a time.
Reasons:

Finding a buyer who wants, and can afford more than one, will narrow the number of buyers.

Most guys will not want to pay for more than the one or two engines that they actually want.

The cost of rebuilding an engine may easily exceed what you can sell it for.

Same thing for the transmissions. (BTW, the T-10 was a borg warner trans. I think you mean M22.)

If you get to the point that you have a few of the less popular things left.... and not much interest.... then you might sell them as a lot, just to finalize the project.