Valve Seat Correction Angles
WARNING: This page is about a different car, the 1992 Mercury Tracer, 1992 Ford Escort, 1991 Mercury Tracer, and 1991 Ford Escort. However, it is still accessible from the selected car via links, so may be relevant.
After grinding seat, to lower the seat, use an 18 degree stone to remove stock from top of valve seat on all valves. To raise the seat, use a 77 degree (intake) or 70 degree (exhaust) stone to remove stock from bottom of seat.