Dodge R1500 1999 Service Manual page 937

injection pump timing, cylinder No. 1 at TDC on compression
stroke and timing pin is engaged in machined hole on camshaft
gear.
Installation
1) Check pump mounting surfaces at pump and mounting flange
for nicks, cuts or damage. Check "O" ring surfaces for nicks, cuts or
damage. Clean injection pump mounting flange at gear housing. Clean
front of injection pump. Install new "O" ring on pump mounting area.
Apply clean engine oil to injection pump "O" ring only.
CAUTION: Ensure fuel injection pump drive gear-to-shaft mating
surfaces are clean and free of oil to provide proper seating
of fuel injection pump drive gear on shaft of fuel injection
pump.
2) Pump/gear keyway has an arrow and 3-digit number stamped
at top edge. See Fig. 12. Position keyway into pump shaft with arrow
pointed toward rear of pump. Ensure 3-digit number stamped on top of
keyway is identical as 3-digit number stamped on injection pump data
plate. If incorrect keyway is installed, a Diagnostic Trouble Code
(DTC) may be set.
Fig. 12: Locating Keyway Arrow & Keyway Number
Courtesy of Chrysler Corp.
3) Position pump assembly to mounting flange on gear cover
while aligning injection pump shaft through back of injection pump