There are two sets of brackets, the brackets from the rubber mounts to the engine block and also, the ones from the rubber mounts to the frame.
If I understand you correctly, you need just the ones from the rubber mounts to the frame.
ONLY in 67 production, these are the same on 289 engines.
Many people needing new 67-only rubber motor mounts THAT ARE NOT REPRODUCED, end up changing the frame brackets to the 68-up type.
This can be another (more affordable) way to find them.
Good luck in your search...those who KNOW, know this and those who DO NOT, often sell at a very reduced price