Crown Victoria V8-281 4.6L SFI (1998)
Valve Seat: Testing and Inspection
Width
Using a seat width scale or a machinist's scale, measure the seat width. Narrow the seat, if necessary, to bring it within specification.
If the valve seat width exceeds the maximum limit, remove enough stock from the top and/or bottom edge of the seat to reduce the width to specification.
On the intake and exhaust seats, use a 60-degree angle grinding wheel to remove stock from the bottom of the seat (raise the seats). A 30-degree angle
wheel is used to remove stock from the top of the seats (lower the seats).