Jeep builders aren’t solely limited to the factory style engine and trans mounts. For each build custom mounts are available. In many applications, factory type mounts will suffice but at a certain point a custom set of mounts may need to be considered. The types of mounts on the market will each have distinctive characteristics that may or may not be desirable and you will need to be aware of this while shopping.
Solid Mounts: Most engine mounts will use some sort of rubberized bushing to eliminate vibration and noise. Solid mounts ditch the shock absorbers and solidly connect the drivetrain to the cross members.
This is sort of a taboo concept because it increases the feel between the driver and the car but can be very hard on mechanical parts. For a Jeep, you will want to avoid these types of mounts. The excess vibrations can shake plastics and screws loose and may also be extremely hard on the transmission.
Polyurethane Mounts: Many aftermarket motor mounts will use polyurethane in place of the rubber that is used from the factory. The reason to use these types of bushings on engine and trans mounts is exactly the same as you would use them for suspension parts.
They are much more durable and will flex much less than rubber bushings would. In the case that you are beefing up the Jeep in any sort of way, you will want to consider the use of polyurethane drivetrain mounts.
Drivetrain Swap Mounts: In the case that you are looking to run a custom drivetrain, you will need to run custom engine mounts. If you are swapping an LS, third-gen Hemi, or any other combination of engine and transmission that isn’t stock to the Wrangler, the custom mounts will either need to be purchased or fabricated. Many aftermarket suppliers will produce these components but it is still a hurdle to be aware of.