A service replacement cylinder head includes the
exhaust valve guides, valve seat inserts, water nozzles,
Check the cylinder liner flange heights with
injector tubes, pilot sleeves, bridge guides, valve spring
seats and the necessary plugs. In addition, studs, cover
plates, gaskets, lock washers and nuts are provided to
2. Make sure the piston crowns are clean and free of
seal the water outlet openings that are not required on
certain engines. A length of flexible fuel hose and
3. Make sure that each push rod is threaded into its
fittings are also included where required.
clevis until the end of the push rod projects through the
Injector clamp bolts or studs are not included and it is
clevis. This is important since serious engine damage
necessary to use new parts or transfer the old parts to
will be prevented when the crankshaft is rotated during
the new head. Injector clamp bolts are interchangeable
with the former studs and nuts; the special washer is
4. Check the cylinder block and cylinder head gasket
used with either the bolt or stud.
surfaces, counterbores and seal grooves to be sure they
Assemble Cylinder Head
are clean and free of foreign material. Also check to
ensure that there are no burrs or sharp edges in the
After cleaning and inspection, assemble the cylinder
head as follows:
5. Inspect the cylinder head bolt holes in the block for
1. Coat the threads of the plugs with Loctite Pipe
accumulation of water, oil or any foreign material.
Sealant with Teflon, then install the necessary plugs and
Clean the bolt holes thoroughly and check for damaged
Drive headless plugs flush to .0625" below the surface
of the cylinder head. The 3/8" socket head oil gallery
6. Check the four corner plugs or drive pins, used to
plug, at each end of the head, must not protrude more
plug the vertical oil galleries, to ensure that they are
than .0625", and a .2187" diameter rod placed in the
flush with or below the top surface of the cylinder block.
vertical oil feed hole must pass the inner face of the
plug. Refer to the Cylinder Head Plugging Charts at the
Install Cylinder Head
end of this section.
1. Refer to Fig. 11 and install the water and oil seal
2. After the following parts are cleaned, inspected and
rings and compression gaskets as follows:
replaced if necessary, reinstall them in the old cylinder
head or transfer them to the new head.
NOTE: Never install used compression
gaskets or seals.
a. Exhaust valves, valve seat inserts and springs
b. Cam followers, guides, push rods, springs,
a. Place a new compression gasket on top of each
retainers, rocker arms, shafts, brackets and
cylinder liner. A new cylinder liner compression
gasket with improved sealing capabilities is now
c. Place new washers on the fuel connectors.
engines built after July, 1979. The new gasket
Then install the connectors and tighten them to
can be identified by GM-MC-H, GM-VG-H or
40-45 Ib-ft (54-61 Nm) torque.
GM-FPH. The compression gasket is also color
d. The fuel injectors, fuel pipes, injector control
coded black, orange or white. The service
tube assembly and water manifold can be
gasket kits will only include a single color (black
installed at this time or after the cylinder head is
Only one color compression
installed on the engine.
gaskets (seal) can be used under a single
e. Attach the engine lifter brackets temporarily to
cylinder head to provide proper clamping.
the cylinder head, without gaskets, to permit
lifting the head into position. The lifter brackets
The new cylinder liner
must not be permanently attached until the
cylinder head attaching bolts have been
interchangeable on an engine under the
installed and tightened to the specified torque.
same cylinder head with the former
Mixing of the
former gasket with the new gasket could
result in uneven loading.
Make the following inspections just prior to installing the
cylinder head whether the head was removed to service
only the head or to facilitate other repairs to the engine.