Here’s a pro tip that’ll save you thousands: change the lift pump before it fails. The factory lift pump on a 12-valve is marginal, and if it dies, your injection pump can starve and grenade itself. Install a FASS or AirDog system, and you’ll have peace of mind for another 100,000 miles.
Another easy win: check the KDP (Killer Dowel Pin) on the timing case. It’s a small metal pin that can fall out and destroy your engine. You can buy a fix-kit for $30 and install it in an afternoon. It’s the one job every 12-valve owner should do the weekend they buy the truck.
Keep your tires at 65 PSI in the rear when you’re not hauling—this isn’t a car, it’s a heavy truck with stiff sidewalls. Overinflating on pavement leads to a kidney-shaking ride. And please, never warm it up by idling for five minutes. A 12-valve prefers a gentle low-throttle drive after thirty seconds—idling just wastes fuel and glazes the cylinders.
