But if it was me I would not bogart the 616 engine, they're probly gonna become scarce in good used running condition in a few years. You will probly need a hoist to pull the 617 iron head, heavy bastard. Whats the circumstances of the 617 engine, mileage, symptoms, etc? Have heard they deserve valve work at/near 280/300k miles..... secret of longevity to get 500k outa the block.

(edit: otherwise salvagable parts from the 616 oughta include manifolds if they're pre-1980 uncluttered with EGR valve.... probly worth a bottle of bourbon at least.