Another muffler was purchased from Advance Muffler and Auto Service in Pasadena on March 24, 1981. This is around 12,000 miles since the last replacement at Midas Muffler Shop. I think this is the 4th muffler on the MGB. It’s amazing how technology has changed. My Subaru is now 13 years old and has 120,000 miles ans still is on the original muffler.