Well.... These things were known as knuckle drives, because of the knuckle shaped coupler on the input shaft. They must only be driven with the drive tilted all the way in or you will strip these knuckles in short order. The engine trimmed by a screwjack on the front of the engine that tilts the whole engine and drive together as a unit, the tilt motor you mentioned is exactly that, for tilting only, and seem to be a bit weak in the motor section. Never tilt the drive on land without assisting the drive on the way up, it needs buoyancy assist of the water to take the load off the motor. The worm gear on the side of the tilt must be drained and filled regularly with gearlube. The bellows at the transom seal must be carefully inspected for holes as mice love to chew holes in the rubber during layup on land, so be careful here. There are three separate drain and fill points on the stern drive, upper housing, lower housing and transom plate and they each must be dealt with individually from each other, best to consult a manual for this. Shifting is done by cables and ignition interrupter switches which unload the shift clutch dogs by cutting out engine cylinders, and must be set correctly. Parts are getting tough to find for this drive but what it does it actually does very well. Get the manual, maintain it by the book and cross your fingers.
I've had several, if you have power steering, good luck. The most reliable is the direct shaft steering connected to the unit itself. Keep the gear oil changed regularly, the seals leak alot. If you have electric shift use the proper lower unit lube, not regular gear lube. Keep an eye on the seals for the water pump because they have a tendancy to suck air. The units tilt up nice and high which makes them really good if you want to beach in the sand.