I have been rebuilding a few (the spring replacement and re-weld repair) and the re-pops say there is a Left and Right. Are the OE ones stamped with a left and right ?All of my units have a L on them ????.I also have a pair of 67s that appear to be side specific. The units I have are for a 1966 .Any help will be accepted thanks in advance. My guess is the 66 s are not side specific ?