Thom,
      
     The only difference you can see externaly on a 36hp and a 25hp is the
oil fill cap.  25hp's don't even have a oil fill cap.  Well, they do, but
it's not as obvious as the 36hp engines.  If you could see a 25hp, you'd know
what I mean.
                    I hope this doesn't confuse anyone.
                                                     Later,
                                                        Eric Stollsteimer

P.S. I'm looking for a 25hp for my '52 Standard Microbus.  If anyone has a
lead on one, please let me know.  By the way, I have a complete, but not
running 36hp for trade.