Nah, those headers will go in super easily. With a tubular K you probably won't even have to drop the starter. Even on jack stands you wouldn't have a problem. That's a lazy afternoon job
Plugs are super easy on a 4th Gen with headers, especially if you have a 1" extension and a swivel head ratchet.
Plugs are super easy on a 4th Gen with headers, especially if you have a 1" extension and a swivel head ratchet.