Originally posted by DeaconBlue:
The ATX wires are 1"-3" longer per lead than the MTX wires. So if you don't route them through all the clips and retainers, the MTX wires may fit on an ATX engine.
Don't count out the aftermarket wire sets. ACCEL, BWD, Bosch, Taylor and the later Magnecore (as well as Niehoff for our friends north of the boarder) wire sets all use the correct configuration/height spark plug boot and seals the well just like the Motorcraft wires. They all combine the MTX and ATX applications (so they all use the ATX's longer lead lengths). Plus these aftermarket sets use a low resistance spiral core wire construction vs. the high resistance carbon/graphite core in the Motorcraft wire. This allows more energy to reach the spark plugs, which is a good thing. Best of all, the price of the aftermarket sets (expect Magnecore) are actually less than the Motorcraft sets.