/What is the best way to ship
the engine from its home in New York State to Boston
area and eventually back here to Michigan?/

When I bought my engine from Boston Bob, he shipped me the rebuilt engine
in a wooden crate using Consolidated Freightways, I then shipped him my
core in the same box, all paperwork and costs were prepaid by Bob, call him
(he doesn't read his mail much, guess he's busy with engines)
and he will guide you.  Maybe when he ships you the engine, you can ship
the crate to your core engine guy and he can ship the core to Bob.

JB