By 1985, torsion spring setups mounted above the door had mostly replaced the old side-mounted extension spring systems, so most Great Falls garages are working with a torsion bar and a pair of springs rated to the door's weight - standard stuff, but the springs still fail on a schedule, usually somewhere past the decade mark, regardless of income or build year.
What does track with the era and the income figure here ($250,001, F7) is the door itself: heavier insulated steel or composite panels are more common on 1980s-and-later construction than on the older stock closer to Vienna, and that insulation earns its keep given the cold-severe climate band this whole area sits in. Openers from this era are often chain-drive units well past their working life, even if they still limp along.
One honest limit: if a panel or spring is a discontinued size from a builder-installed door of this vintage, we may need to order the part rather than pull it off the truck, and that adds a day or two - worth knowing before you schedule.