I asked this question over in the Restoration forum as well.

In the tech archives there is a specific part number for the 1969 B Body Hemi 4 speed manual trans mount - 2660673.
Anyone know what the difference is between this mount and the 2533145 mount?
Can the 2533145 mount be used in place of 2660673?
Thanks

I thought (based on what I had read here when this topic came up previously) that Hemi cars used a different colored rubber (yellow, maybe?) and a higher density rubber, hence the different part number.

As long as they're the same type (spool?), they should interchange.

No spool mount in 68 or 69. They used a block type mount that dropped into a pocket on the front of the cross member for automatics, or in the middle of the crossmember on manual trasnmission cars. There is a difference of cross members.