Just a few things i either missed or something. 1) is it the EFI 5.0? If it is, I had the same problem. Turned out there are two different designs of alternator for that motor. You may want to look into this. Also, streets is right about the pull and die syndrome. Unless you own an AMC. We're dinosaurs. Finally, ther was just a massive recall on the ignition module for the ford V8s. Causes cut-outs, hard starting, ignition problems, you may want to ask your local ford garage about this.