Dodge D250 1990 Service Manual page 352

Base Engine Components
DODGE Turbo Diesel
Alternative Repair Procedures
Page9K-21
Install the valves in their respective bores and measure the T p j
depth again. \jL/
Record the depth of each valve (B).
Calculate the grinding depth (GD) as follows:
GD = (B)-(A)
Grinding Depth Maximum Limit (Integral Seats Only)
GD = .254mm [.010 inch]
Note: Service valve seats are available for over the limit seats.
Identify reground valve seats.