I'm in the process of restoring an air cleaner for a '68 400. From searching through all of the threads and reviewing photos of "concours" cars I find the air cleaner service decal (white letting on clear, noting 6424827 p/n) but I have not been able to find info for the correct location for that decal though it appears it may go around the 12 0'clock position just about in line with the upper radiator hose. Does anyone have information on where that decal would have originally been placed? Also, on a few cleaners there was a "Keep your GM car all GM" decal along with the service instruction decal. Were both decals as original and if so, any info on the location for the "Keep your GM car all GM" decal?

The air cleaner lettering was silk-screened, not a sticker. There was a guy over on PY that made up a screen to replicate it. Not sure if a search over there would find it. I'm guessing I remember reading about it 3-6 years ago?

The "keep your GM car all GM" may not have been placed on all cars. I've seen a few very originals without it, and a few people that have sworn they all came with it. (my very original '68 did not have it) My opinion was those came on 350 cars, and not 400 cars. But hard to prove otherwise.

The various other engine bay stickers seem to have been placed wherever the assembly line guy felt like at that moment. I've seen those all over the place as well.