You need compression, fuel and spark. You are missing one of those.
Screwed in the heads.
i know if you have the 5.4L V8 you will have coil packs. not spark plugs
have misfire on #5 on a ford f150 4.6. changed spark plug and coil pack and injector.
for what size of engine ?
.044 inch
If your Ford Aerostar sputters at high speeds, you might have a problem with the fuel injection system or with the fuel filter. You could also have water in the fuel lines, bad gas, or even a spark plug fouling issue.
If you didn't replace one spark plug wire at a time you may have mixed up the firing order.
.044 inch
.044 inch
.044 inch
.054 inch