[jeffschevelle]

3886466 is the part number shown for 67 Camaro 396 in the July 1967 parts book revision. Those are the ones without an affixed nut on either side.

The 67 Camaro AIM does not show mounts in L35/L78 sections, which means they should install same as the 283 small block V8 mounts as shown in Section 6. Section 6 shows mounts without any affixed nuts and shows a loose washer and nut being used. So 3886466 is most likely assembly line correct.

Trivia - 65-67 Chevelle 396 assembly line mounts were the exact same design mount except with an affixed nut on the rear facing side, so they are left-right specific. (It is all but impossible to find a good set of those.) The 67 Chevelle part numbers were 3886467 and 3886468. But the initial service replacement part was 3886466 for both sides (supply your own nut, I guess).