Drum brake installation troubles...

Now just wait a minute:

Are you sure you have the right cylinders, or are they original?

Did you check the length of the old/ new adjusters and cylinder push-rods?

Are the drums new or the old ones?

They "should fit." if not, the lining is probably incorrect and oversize.

(The factory did not go around turning out new drums)

I spose in this day and age of quality control issues, anything is possible.