1953-1960 Classic Car Engines Troubleshooting Guide: After-Burning
Things to Look For:
A subdued put-putting at the exhaust tail pipe may be due to leaky exhaust valves which permit the mixture to finish combustion in the muffler. If exhaust pipe or muffler is red hot, better let it cool, as there is some danger of setting the car on fire. Most likely to occur when mixture is lean.
The Complete Guide to Troubleshooting 1953-1960 Era American Classic Car Engines