Main concern is the rings frozen in the bore and stuck valves. I remove all the spark plugs and valve covers and oil down the engine with oil and PB blaster daily for a few weeks. And slowly work it free You can even just remove the rocker assy to avoid that issue completely. I do the tap and set for rusty bolts. Spray the penetrating oil onto the bolts and tap them with a brass drift and hammer. A torch is good too. The main thing is you want to get it apart without issue. That could be a problem is the car is an hour away tho. Now the other thing is maybe have him pull the engine and then give it the once over. Look at the back of the block for any sandscratchs. A or S would be a 428. Maybe ask to remove the oilpan and see how the internals are and ID the crank. It could be a 360 or 352 for all we know.

G.