Motor mount rubbers

I have a 67 valiant signet and I am putting a 79 or later 360 in it with a 727 trans. The car came with the correct motor mount brackets for the slant 6 to V8 swap. The rubber for the motor mounts need to be replaced. The mounts that were on there were two different thicknesses. Is this correct. And I am having trouble finding the replacements online. Thanks in advance.

Dave