Austin, I can't say for sure (I never compared them directly), but I believe the Surgilators were the same in both standard- and super-capacity machines for a few years leading up to the Double-Duty. Notice the fill levels on these pictures:
This is a 1983 super-capacity electronic control machine, with a winged Surgilator.
This is a 1961 standard capacity machine.
Both of them leave a couple inches of agitator exposed.
Our 1976 super-capacity LDA-7800 Supreme 80 filled to the level I've marked in red on the 1983 pic -- ALL the way to the TOP of the agitator / bottom of the agitator cap. Thus, the same size agitator used in a standard capacity machine handled an 18-pound load by way of a higher fill (relatively).

This is a 1983 super-capacity electronic control machine, with a winged Surgilator.
This is a 1961 standard capacity machine.
Both of them leave a couple inches of agitator exposed.
Our 1976 super-capacity LDA-7800 Supreme 80 filled to the level I've marked in red on the 1983 pic -- ALL the way to the TOP of the agitator / bottom of the agitator cap. Thus, the same size agitator used in a standard capacity machine handled an 18-pound load by way of a higher fill (relatively).
