so I have been searching on here and cant seem to locate the help I need. I have a 14.5 briggs ohv, almost positive this isnt the original cover and when I am looking up new pistons and rings I am finding the code determines wich piston (choice between 2) I need. can anyone tell me the difference in the two? I am going to bore the cylinder so I am curious how much this "code" affects me. any help will be appreciated. I have numbers stamped on the piston but was told by the local rep they were of no use. also no other shrouds are present on the motor and it does not have the original valve cover.thanks guys