At 55,000 miles I noticed blue smoke at start up in the mornings and after it had sit all day at work. I have noticed some piston slap if I get on it some but not at start ups with the blue smoke. Using a lot of oil. I bought the truck with 29000 miles and have changed oil every 3500 miles using valvoline 5w 30. I took it to a ford mechanic and he says he is not sure why it smokes so bad at start up after sitting for awhile. He checked things out for me but said he couldnt help me. Please help. I now have 64,000 miles and the smoke at start up is getting worse. Still runs fine and no piston slap unless I get on it hard.

 

Sounds like valve guide seals are bad.

Does the engine have any/much slugge??

 

Welcome ! Check the PCV and the entire PCV vacuum line. This is one common problem that causes those symptoms. The PCV can get scummed up and the vacuum line degenerates over time and can develop cracks/leaks.