We start with the header and the track, not the opener box, because a unit built for a 1968 door doesn't always mount clean on hardware that's been re-shimmed or repainted over the years. Belt-drive units go in quiet, which matters more in Greece's attached-garage layouts where the bay backs straight onto a bedroom or den. Chain-drive still makes sense on heavier doors or where budget is the deciding factor. Either way we're setting the travel limits and force settings to match the door's actual weight, not a factory default, because a door from this era rarely weighs what a new one does. We also check the safety sensors are aimed correctly and mounted at a height that clears whatever's stored along the garage walls, since older Greece garages tend to double as storage, not just parking.