I have 168000 miles on my truck. Im replacing tensioners but not sure if cam phasers are worth replacing.

 

If you are planning on keeping the truck, at that mileage, it would be very advisable on a 5.4L. What if they fail 20K down the road? Me, personally, if I DIY and get wholesale on parts, whatever reasonable I touch gets replaced. Then I have years of worry free driving.

Also, the rockers are known weakness, there are even TSBs about it. If you are in there, it is very advisable to replace those.

Some even say to upgrade the oil pump.

 

I recently replaced my cam phasers, chains, rockers, oil pump, solenoids, and anything else I could while in there. I bought the truck from a neighbor with almost 200,000 on the odometer. Never thought I would buy a truck with that much mileage but I could not believe the shape it was in. When I tromped on it the other day to pass a few vehicles the engine performed beautifully. It is quite the DIY if you are game. I was and I am glad i did.

 

I was considering some higher mileage 5.4's and that would have certainly been on my list. Lucky it was caught in time. You should get another 200K (or more if you maintain) out of it. Expeditions got the 5.4 until '14.