Chevrolet 1977 light duty truck, Service Manual

Page: 500 / 861

compressor tool, m ak in g sure the locks seat properly in
the groove o f the valve stem.
N O T E : G rease may be used to hold the locks in
place, while releasing the compressor tool.
3. Install the r e m a in in g valves.
4. On Small V8 engines check each valve stem oil
seal by placing Valve Seal Leak Detector (Toool J-23994)
over the end o f the valve stem and against the cap.
O perate the vacuum p u m p an d m ake sure no air leaks
past the seal (fig. 6A-29V).
5. Check the installed height o f the valve springs,
using a narrow thin scale. A cutaway scale will help (fig.
6A-30V). M easure from the top o f the shim or the spring
seat to the top o f the valve spring or valve spring shield
(fig. 6A-31V). If this is found to exceed the specified
height, install a valve spring seat shim approxim ately
1 /1 6 " thick. At no time should the spring be shim m ed to
give an installed height u nder the m in im u m specified.
Installation
CAUTIO N: The gasket surfaces on both the
head a n d the block m ust be clean o f any
fo reig n m atter a n d fr e e o f nicks or heavy
scratches. Cylinder bolt threads in the block
a n d threads on the cylinder head bolts m ust be
clean. (D irt will affect bolt torque).
1. On engines using a STEEL gasket, coat both
sides o f a new gasket with a good sealer. Spread the
GR IN D OUT THIS PO R TIO N
i | i| II i
j 1 1
1 j I p
1
1
1
I ' l ' l ' l ' l " 1—
r ...... ..
l '
r~rj
" I " ’ ! ”
1 1
2 3 4 5 6
Fig. 6A-30V--Cutaway Scale
sealer thin and even. One m ethod o f applying the sealer
that will assure the p ro p er coat is with the use o f a paint
roller. Too much sealer may hold the gasket away from
the head or block.
CAUTION:
Use no sealer on engines using a
composition S T E E L A S B E S T O S gasket.
2. Place the gasket in position over the dowel pins
with the bead up.
3. Carefully guide the cylinder head into place
over the dowel pins and gasket.
4. Coat threads o f cylinder h ead bolts with sealing
com pound and install bolts finger tight.
5. Tighten each cylinder head bolt a little at a time
in the sequence shown in the torque sequence chart until
the specified torque is reached.
6. Install exhaust manifolds as previously outlined.
7. Install intake m anifold as previously outlined.
8. Install and adjust valve mechanism as previously
outlined.
ROCKER ARM STUDS
Replacement
M ark IV
T he push rod guides are related to the cylinder head
by the rocker arm studs (fig. 6A-32V). Replace where
necessary and torque rocker arm studs to specifications.
N O TE: Coat T hreads on cylinder h ead end of
rocker arm studs with sealer before assembly to
cylinder head.
Sm all V8
Rocker arm studs that have d a m a g e d threads or are
SEE SPECIFICATIONS
Fig 6A-32V -Rocker Arm Stud
Push Rod G uide