Surprise, Guys!
Well, here's the thing. Remember when machines in general changed the tub size from 10 pound capacities to 12? Around 1964 or so.
I remember my Aunt Margaret's 64 Frigidaire had the new 12 pound load size. Likewise, the conventional wringer washers changed their tub sizes as well. The KM 61 is 13 & 1/2 inches deep, while the 66 hops up to15 inches; the 61 straight vane will not work in the 66, nor will the 66's Root-swirl properly fit the 61. Since Joe's machine has the Roto-swirl, that must have been the year of the change over in capacity for Kenmore Conventionals, 1964, the same year for many automatics.
Sweet surprising irony in the fact that you can switch among many brands, but sometimes, not within them. What we need to find and see is the Agitator used in early Whirlpools before the Surgilator. You're seeing the solution here, gentlemen: The Surgilator and the Roto would be interchangeable, so would WP's early 3-vane with the KM 3-vane; but not the other way around. John is right in that the Automatics are not interchangeable with the Conventions. I've tried them all to certain disappointment.
I wonder if we have pictures anywhere of this first Whirlpool agitator.
Pic talk: The first mark is the 15 inches the tub depth measurement of the 66; the second, the 61. Here's the Roto-swirl in the 61 whose business end can't bridge the gap.
