Can I use both the MACE Performance 12mm upper and lower manifold insulators for Ford at the same time?

Yes, you can use both, but whether it’s the best option depends on your application and driving style. If you had to choose just one, we generally recommend the lower manifold insulator first, as it usually provides the most noticeable gains. That said, you’ll see benefits from either upgrade, and using both together can further enhance performance if installation space isn’t an issue.