So since I'm getting close up there in mileage I'm wondering what is the best bet on getting important things done before problems start showing up. I just had my rear differential rebuilt. And now I plan on changing the spark plugs.

Are there any other important things that need to get changed out? I know I have the maintenance manual but I'm mainly looking for the most important things at the moment that should be getting looked at soon

 

I have a 5.4 btw

 

Your spark plugs are due, and are potentially the most expensive thing you can do.

 

I don't want this to come out wrong but I'd take a hard look at the manual. I've followed that religiously and it hasn't failed me yet. Things I would add to the list if not previously done would be; front and rear differentials, transfer case oil, serpentine belt and definitely a coolant flush. I may be wrong on the transfer case but the cooling system and belt I feel sure of.

I think regular coolant maintenance is essential to radiator and heater core life.

Best of luck to you.