Dana 60 under 73 swinger..need id

Ok more news on the Dana 60
Rear passenger wheel cylinder is fried..




It's really small for a Dana 60
3/4" bore wheel cylinders

Btw
27.75" equal length axles
55.5" wms

I know I need to replace it
but how to ID it for the part shopping is another question I tried that J truck approach that didn't work out
Also I believe they are 10 by 2" drums