I have a 318 that has become a huge project, dead motor. I just found a 316 on CL with a 16hp Vanguard in it. For a few hundred more than a Briggs motor alone I could buy the machine and get a mowing deck that I need too. I'm wonder how compatible these machines are?
I would consider taking the engine, mower deck and all the sheet metal off the 316 and installing it on the 318 Frame and hydro.
Who knows if my plan would work?