And where did you put the washers?? if you put them between the crank pin and the rod you moved it back more///// Remove the washers make sure the prop drive washer is firmly seated on the shaft this will pull the shaft foward and the rod with It is normal
in some engines to have a very slight rub mark on the back plate. If the main bearing is not firmly seated in the case this will allow\the shaft to be displaced rearward on re reading your post I assume now you put the washer between the rear cover and the engine case
hence you did not move the crankpin/rod back