I have actually opened many of them, back in "the day". To convert yours to short shaft you have to find a short drive shaft and short upper shift rod. You can cut exactly 5" off the water tube.
I just rebuilt a 1973 25hp long shaft. NO it's not the same engine and lower, but VERY similar. All these engines have literally about the same parts. They have to have all the same stuff. They all have water tubes drive shafts and shift shafts. You can buy it piece meal off eBay useing short shaft part numbers but chances are you will pay as much or more than buying a short shaft motor and swapping parts. Go to old school marine mechanics or guys into vintage stuff. They will possibly have them laying around.
