The 1971 60 HP uses 2 water tubes and the pump housing in the correct kit has 2 holes in it. In 1972 the engine was changed to a 65 HP with a single tube water pump.
You may have the wrong gearcase or the wrong water pump kit. Contact your dealer to have a tech look at what you have, or contact the seller of the gearcase and the kit.
"There is never just one thing wrong with a boat";
-- Travis McGee, main character in a book series by John D. McDonald
The factory recommends that a properly trained technician service your Johnson or Evinrude outboard motor. Should you elect to perform repairs yourself, use caution, common sense, and observe safety procedures in the vicinity of flammable liquids, around moving parts, near high-temperature components, and working with electrical or ignition systems.
The information offered here is only general in nature and should not be construed as complete factory approved procedures, techniques, or specifications. Always use the proper service manual for your motor, up-to-date service literature, the correct tools, and have an understanding of how to proceed with troubleshooting and repair methods. If you are unsure or uncomfortable with a procedure, a situation, or a technique, enlist the services of a factory trained technician.