Location of plugs are passenger side front to back 1-2-3-4. Drivers side front to back 5-6-7-8. If you have the 4.6L V8 you may want to look at this: http://autorepair.about.com/library/firing_orders/bl-fo-5298.htm
There 8 Spark plugs not 4.
The are no distributor cap on the 1997 Ford Expedition. You have eight coil packs one on each spark plug.
Driver's side front
.054 inch for the 4.6 liter and 5.4 liter engines according to the 1997 Ford Expedition Owner Guide
Third one back on the driver's side
The recommended spark plug gap for a 2003 Ford Expedition 4.6 is .054"
No , the Ford 5.4 liter V8 engine has ALWAYS had the Coil On Plug ( C.O.P. ) ignition system with ( 8 ) individual coils In a 1997 Ford Expedition , the 4.6 liter V8 engine uses ( 2 ) coil packs and ( 8 ) spark plug wires
According to the 1997 Ford Expedition Owner Guide : For the 4.6 and 5.4 liter V8 engines : ( .054 inch spark plug gap ) * confirm with the Vehicle Emission Control Information ( VECI ) decal in the front of your engine compartment
( .054 inch ) according to motorcraft.com
firewall 4 - 8 3 - 7 2 - 6 1 - 5 front of Ford Expedition
firewall 4 - 8 3 - 7 2 - 6 1 - 5 front of Ford Expedition
Check under the hood decal info.