I purchased a water pump kit for my 90hp Johnson motor. In the instructions it says to use 3M 847 Adhesive when installing the orings and grommet. Since this was my first time doing this, I asked the man at the service counter if there was any adhesive or gasket sealer I needed to buy along with the kit. He said I did not need anything, everything was in the kit. Since I did not purchase this item at the time I bought the kit, how important is it that I use the adhesive? If it is important that I use it when I replace the water pump, can I purchase it at a local auto parts store or sporting goods store? Can I use something other than the 3M adhesive they recommend in the instructions?