D 350 Pickup L6-359 5.9L DSL (1989)
Fig. 43 Valve Guide Installation (Thick Wall Guide)
To determine guide replacement, measure valve guide bore diameter, measurement should be 0.31257 - 0.3185 inch. If valve guide bore is over
maximum limit, install service guides using the following procedures. New valve guides must be reamed to size after they are installed.
1. Install thin wall guides as follows:
a. Machine cylinder head valve guide bores to 0.4380 - 0.0005 inch, Fig. 40. Service valve guides must be centered with valve seats within
0.01378 inch diameter and are to be square with the combustion face within 0.0004 inch at 1.9685 radius.
b. Using a suitable press, install valve guides, Fig. 41. Valve guide bore must be centered with valve seats within 0.0138 inch diameter and must
be square with the combustion face within 0.0004 inch at 2.0 radius.
2. Install thick wall guides as follows:
a. Machine cylinder head valve guide bores to 0.5512 - 0.0005 inch, Fig. 42. Valve guides must be centered with valve seats within 0.01378 inch
diameter and are to be square with the combustion face within 0.0004 inch at 1.9685 radius.
b. Lubricate with oil and using a suitable press install valve guides to 04823 - 0.020 inch, Fig. 43. Ream the bores to 0.3161 - 0.0004 inch.
