I guess the more I ride these panheads - be it a rigid, hand shift, stripped chopper with narrow bars . . . or a late model, dressed, Electra Glide with cushy suspension, wide bars and windscreen . . . the more I like them. That whirr of the motor is such music to my ears . . . no other motor sounds like a panhead. Not really sure what causes that whirring either? Most likely the thin, hollow rocker covers? Or a combination of hollow covers, rocker design and gear drive generator cases. I always run the felt pads, and they supposedly quiet down the sound, and get soaked with oil, and keep parts lubed and wet with motor oil. Who knows? H-D factory parts experimentation continued with model after model on many engines - like the "intake oiler tubes." Most panhead engines I disassemble don't have them in there anymore, and if they do, the little check ball is stuck - so useless. Or it's completely broken off, laying in the bottom around a valve spring collar. The panhead can be the prettiest motor, or the ugliest. The most oiled out, rat-out pan chopper is the scariest bike ever . . . parked next to a gleaming chrome daydream of a '65 Electra Glide, in Vivid Black or Hi-Fi Blue. It's up to you.