My 99 with 5.4 is ready for a tuneup. I know I have at least one bad coil as it labors when I tow at highway speeds. I've had the problem before so I'm confident it's a coil. Since I have 82k on the motor I was thinking of a complete tuneup. Should I change all the coils (after market Granatelli's or stay with oem) and also should would it be best to go with Motorcraft plugs. If I stay with Ford's coil I will just replace the one that is bad. Any other ideas would be appreciated.