Dodge D250 1990 Service Manual page 320

Base Engine Components
DODGE Turbo Diesel
Out-of-Chassis Repairs
Page 91-33
Rotate the engine in the opposite direction until the piston
contacts the plate.
Mark the vibration damper.
Mark the vibration damper for TDC. TDC will be one-half the
distance between the first two marks.
19mm
Remove the plate and rotate the engine In the direction of
rotation until the pointer aligns with the TDC mark.
Look for the timing pin hole In the camshaft gear. If It is not
visible, rotate the crankshaft one complete rotation. Align the
pointer with the TDC mark.