The scenario; Pre-'16 ride in Atascadero, 2007. My 1928 Sunbeam TT90 was running poorly and backfiring, not up to its usual peppy performance. On investigation, the inlet pushrod had worn through its hardened tip, and was making a shiny steel/grease grinding paste inside the rocker arm cup. Knowing the whole pushrod/rocker assembly would shortly be scrap, I swapped my inlet and exhaust pushrods to continue the ride...which went just fine, power restored, and the roads through the hills were magic in the Spring. I followed a Crocker through a few turns but got tired of watching his footboards scrape the road - the Sunbeam has no such issues, with racing footrests and 21/20" wheels.
Thanks to Jerry Kaplan for sending the scan!