I have the same motor and I plan to start it for the first time in a few days. It came with the same card saying it was run for 20 minutes, and what temp it got up to and I think
oil pressure or some other tidbit. And the plugs have a touch of color, and a little but of residue in the exhaust port, so it was running on some hydrocarbon. Also, there was a little rust in the bottom of the water pump where it couldn't fully drain.
I guess they have a o ringed intake they can quickly strap on, and a
oil pump drive gear or maybe a full dizzy they slap in. The balancer also had paint mark on it for timing.