I would humbly suggest to consider the operating environment for a bit before choosing a material
I’m not sure where exactly this mount is
But if it’s like my trucks that whole area is messy and hot with trace amounts of everything found in the engine bay
If the part will be exposed to motor oil or traces of gasoline then perhaps neoprene is not considered a suitable material as it score at the bottom of chemical compatibility charts for both of those items (unacceptable for use in contact with/)
Heat and incompatible chemicals is going to lead to premature failure
Sure it might last a while but it won’t be anything like using a compatible material while going though the effort of rebuilding it.
What I do in cases like this,
Look up chemical compatibility charts online
Make a list of the best few materials for your application
hunt sources for those materials while considering how you would mold or machine them for your application
-s
