Jon <br
Unless you're working with a rare super-tall centerpost 196?-1973 large capacity machine, ALL the belt-drive agitators will fit in all the machines. The Straight-Vane, the various Roto-Swirls, the Vari-Flex, the Roto-Flex, and the two Whirlpool Surgilators are all interchangeable and meant to be used in standard capacity tubs. The early bakelite agitators will require drive-blocks to be installed in newer machines. <br
The Penta-Vane, the Penta-Swirl, the large Surgilator, and the Double-Duty Surgilator are also all interchangeable in the large capacity machines. These will fit in a standard tub machine (they look majorly funky). A Penta-Vane in a standard tub though is beyond amusing. Putting a standard agitator into a large machine can be done also, but high water levels can go way too far up the neck of the agitator in the largest machines<br
The Dual-Action's base is the same in both capacities, but they use different augers for the two capacities. So, you can basically put anything into anything, provided you're not dealing with the elusive tallest post models<br
G