I hope that you are using at the very least the engine and transmission mount pair. Really should also use the dogbone mount as well with them.
As a general rule the three mounts together work as a team. If one or two of them is softer or harder you'll end up with odd deflection that can strain multiple things in the drivetrain and exhaust.
TLDR: don't skimp on just replacing one mount. All three should be replaced as a team to help resist excess engine/transmission movement.