The numbers and letters on the side are characteristic of what we used to call the cheap 50 dollar muffler. The 2 spot welds visible in the picture are fastening a baffle inside that is also what the cheap muffler has. There will be similar spot welds for another baffle near the other end of the muffler. Your muffler will work fine, but will provide some flow resistance if your engine is souped up and you are running full power.