* Front doors: 6x8 inches (or 6.5 inches, depending on the trim level. 6x8 is more common)
* Rear doors: 6x8 inches (or 6.5 inches, depending on the trim level. 6x8 is more common)
It's crucial to verify this by physically measuring the existing speakers or checking your owner's manual if you still have it. There's some variation depending on the specific options package of your truck.
