I have seen several posts in the past on the console gauge oil hose grommet 3906193 that was installed in the firewall by the factory. However, I have not seen anybody address whether the original grommet had a slit in it for the oil hose. The reproduction grommet that is being sold today does not have a slit in it (see photo attached). There are many CRG posts of members cutting the oil hose and then using new compression fittings in their restorations. This is warranted for re-using original hose assemblies to prevent leakage at the compression fittings...but not for NOS or new reproduction hose assemblies. I am guessing that everybody is cutting their hoses because neither compression fitting end fits through the reproduction grommet hole and they don't want to cut a slit into the reproduction grommet whereby ruining its "originality"? I am going to make the argument that the original grommet did have a slit in it, about half way between its two embossed text (i.e., embossed text is about 180 degrees apart). There is at least one CRG post that had a photo of what appears to be an original grommet with a slit in it (Camaro Research Group discussion forum "Did console gauge cars also have a low oil pressure switch?" Reply #29 on February 27, 2013, 21:40:52 by Member '67rs/ss396').
I attached copies of the 68 AIM and 69 AIM pages that show the grommet installation. I could not attach the 67 AIM page because of a four attachment limit. I'll attach the 67 AIM page on a reply to this post, if permitted. All three of these AIM illustrations, however, show the grommet with a separate part number than the hose assembly. The hose assembly is shown in the three AIMs with the compression fitting already attached on the engine compartment side. The same holds true of the hose assembly compression fitting under the console oil gauge. Because of the size of the compression fittings on both ends of the hose, and the size of the hole in the grommet, it would be physically impossible to put the hose through the grommet if the grommet did not already have a slit in it. I doubt the assembly line workers had the time to cut the oil hose, push the hose through the grommet, and then install a new compression fitting sleeve on every car with console gauges...and that task is not shown anywhere in the three AIMs.
The solution is simple: Use a razor blade and put a slit in the reproduction grommet half way between the two embossed text. If any of the vendors read this post, maybe they could begin selling the grommets already slit, or at least make a note in their sale advertisement that the grommet will need to be slit to fit the hose.