A service replacement cylinder head includes the
Check the cylinder liner flange heights with
exhaust valve guides, valve seat inserts, water nozzles,
injector tubes, pilot sleeves, bridge guides, valve spring
seats and the necessary plugs. In addition, studs, cover
2. Make sure the piston crowns are clean and free of
plates, gaskets, lock washers and nuts are provided to
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
clevis. This is important since serious engine damage
Injector clamp bolts or studs are not included and it is
will be prevented when the crankshaft is rotated during
necessary to use new parts or transfer the old parts to
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
are clean and free of foreign material. Also check to
Assemble Cylinder Head
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
accumulation of water, oil or any foreign material.
1. Coat the threads of the plugs with Loctite Pipe
Clean the bolt holes thoroughly and check for damaged
Sealant with Teflon, then install the necessary plugs and
Drive headless plugs flush to .0625" below the surface
6. Check the four corner plugs or drive pins, used to
of the cylinder head. The 3/8" socket head oil gallery
plug the vertical oil galleries, to ensure that they are
plug, at each end of the head, must not protrude more
flush with or below the top surface of the cylinder block.
than .0625", and a .2187" diameter rod placed in the
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
rings and compression gaskets as follows:
2. After the following parts are cleaned, inspected and
replaced if necessary, reinstall them in the old cylinder
NOTE: Never install used compression
head or transfer them to the new head.
gaskets or seals.
a. Exhaust valves, valve seat inserts and springs
a. Place a new compression gasket on top of each
b. Cam followers, guides, push rods, springs,
cylinder liner. A new cylinder liner compression
retainers, rocker arms, shafts, brackets and
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.