340 K Member ??
Here's what i've learned from this thread. There seems to be only one or two pre 70 cars that do have the washer. There seems to be a couple of 70 and up cars that dont. It seems the bulk of cars built from 70 and up with a 340 do have the washers and this seems to be a factory identification of some kind. I doubt very seriously that it had anything to do in the machining process as each and everyone are different as far as exact location, which would be necessary for machining purposes. The engine ID would hold water. The sway bar, for now, does hold water. This needs some more research. I'll check my field for the sway bar theory. I know without looking the 1 70 model 340 valiant/duster with washer does have a sway bar. I'll check the other one. For those of you that have washers in pre 70 cars, are you absolutely sure your car is an original K member? Not calling anyone a liar but things do happen to cars that we aren't told about. Also for you guys that have 70 models and up that dont have the washer, are you totally sure no one has done some swapping? You guys check your washered cars for swaybars and report back. We'll get er figured out.
Small Block