I am overhauling a WD.  My new gasket set had two smaller felt seals and one larger round rope type felt seal.  When I disassembled the motor, it did not have the larger round seal in it, just the two smaller felt seals.  Obviously, the two smaller felt seals are the upper and lower rear main seals.  But where does the larger one go?  It looks like there is a groove in the rear main cap that will accept this larger seal.  Do I use all three?  Also, what is the best way to install these seals.  They are really really hard to get into the groove, almost like they will not fit, but I know they will with the right technique.  I have them soaking in oil right now and somewhere I read to then put them iin the freezer overnight.  Any advise is greatly appreciated.

there is no rope seal used on a WD. Sounds like you got a gasket set from the auto parts store, they sometimes come with the rope.    The seals are tough to get in the caps, dont cut anything off the end (at least on the Allis Chalmers seals).    You are supposed to glue then into the groove with special adhesive.  I guess you could get by with some 3M weather srip adhesive, then lightly oil the sealing surfaces.  If you dont glue it in the seal halves will turn as the crankshaft moves, then there is a gap between the seal haves and it will leak oil.  You need to get those seals halves out of the oil and  wash all the oil out or the adhesive wont hold.   HTH  Good luck.