The picture of the inside of the engine shows a copper plated con rod with the center opened up...The pulse port mod is something us engine converters have been doing for at least 18 years, putting the pulse directly into the carb backplate from a fitting in the case...The picture show the pulse fitting in the insulator block under the carb, not the crankcase...If the crank pin was not hard enough for the roller it's the same problem some converters had when putting a needle bearing on the rod in a ST3000...C&H did it for a while and quit when they found out about the soft pin....Right, TKG ?