Extension springs in 1980s
That eight-year gap matters more than it sounds. Doors and openers installed in the mid-to-late 1980s were more likely to ship with extension springs on the side rails instead of the torsion bar setup that became standard through the 90s and 2000s. If your door is original to the house, you're probably looking at that older hardware, plus a chain-drive opener that's had three or four decades to wear down its gears.
