I just replaced my plugs the day before yesterday on my 04 f 150 5.4L..It has 75000 miles on it..Is it nessessary to change the boots too?? The mechanic said the personally he wouldnt but thats just him. Replacing the plugs fixed all my problems so I didnt know if it was needed

 

I ask the following; Would you replace the plug wires at 75,000? If the answer is yes then I would replace the boots. Personally I would replace the boots.

 

I agree, replace the boots, by the time you go in there to replace the plugs again they would prolly be cracked and possibly allow the coils to arc out against the plug well. They are pretty cheap insurance to know you shouldn't need to go back to that are of the motor for a while.