REMOVAL & INSTALLATION
See Figures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12L-6 Engine
- Drain the cooling system and remove the air cleaner. Disconnect the PCV hose.
- Disconnect the throttle linkage at the carburetor. Disconnect the fuel line at the carburetor. Disconnect the vacuum line to the distributor.
- Remove the top radiator hose. Remove the battery ground strap. Disconnect the wires from the temperature sending unit.
- Disconnect the wires from the coil and remove the coil Remove the spark plug wires from the plugs.
- Disconnect the exhaust pipe at the manifold flange. On 1970-74 engines, the intake and exhaust manifolds are removed as a unit. On 1975-76 engines, the intake manifold is integral with the head and cannot be removed.
- Remove the manifold bolts and remove the manifold or manifolds.
- Remove the rocker arm cover. Mark and remove the rocker arms. Mark and remove the pushrods. It is important to mark them as they must go back in their correct place.
- Remove the cylinder head bolts. You'll probably need a breaker bar as they are under a lot of torque.
- Remove the cylinder head. It may be necessary to tap the head lightly with a hammer to break the seal. Don't pry between the head and the block as you may gouge one or the other. Remove the manifold gasket. Generally speaking, it is necessary to scrape the top of the engine block and the cylinder head to remove the gasket.
- To install the cylinder head, first place a new head gasket over the dowel pins in the top of the block.
Different types of head gaskets are available. If you are using a steel-asbestos composition gasket, do not use gasket sealer.
- Lower the cylinder head carefully into place over the dowel pins and the gasket.
- Clean and oil the cylinder head bolts, install them and run them down snug.
- Tighten the head bolts in three stages in the correct sequences. The final torque should be 90 to 95 foot pounds. (122-128 Nm)
- Install the pushrods in their correct openings, making sure they are seated in their lifter sockets.
- Install the rocker arms in their correct position. Tighten the rocker arm nuts until all pushrod play is taken up.
- Install the manifold or manifolds, using new gaskets. Torque the manifold to the specified torque.
- Install the upper radiator hose. Install the coil and coil wires.
- Install the fuel line, vacuum line, and throttle linkage. Install the ground strap.
- Connect the exhaust pipe to the exhaust manifold.
- Adjust the valves. (See the valve adjustment section.) Install the rocker arm cover, using a new gasket. Install the air cleaner.
- Disconnect the battery.
- Drain the coolant.
- Remove the air cleaner.
- Remove the air conditioning compressor, but do not disconnect any lines. Disconnect the AIR hose at the check valve. Remove the turbocharger assembly, (if so equipped).
- Remove the intake manifold.
- When removing the right cylinder head, loosen the alternator belt, disconnect the wiring and remove the alternator. If equipped with A/C, remove the compressor from the mounting bracket and position it out of the way. Do not disconnect any of the hoses.
- When removing the left cylinder head, remove the dipstick, power steering pump and air pump if so equipped.
- Disconnect and label the plug wires.
- Disconnect exhaust manifold from the head being removed.
- Remove the rocker arm cover and rocker shaft assembly. Lift out the pushrods. Be extremely careful to avoid getting dirt into the valve lifters. Keep the pushrods in order; they must be returned to their original positions.
- Remove the cylinder head bolts.
- Remove the cylinder head and gasket.
- Install the cylinder head and new gasket
- Install the pushrods, rocker shaft assembly and rocker cover
- Install the exhaust manifold and connect the plug wires
- On the left cylinder head, install the air pump, power steering pump (if equipped) and the dipstick
- On the right cylinder head, install the AC compressor in the bracket (if equipped), secure the alternator in position and connect the wiring and belt
- Install the intake manifold and the turbocharger (if equipped)
- Install the air cleaner
The engine should be overnight cold before the cylinder head is removed to prevent warpage.
- Drain coolant. Remove the air cleaner.
- Disconnect the negative battery cable.
- Disconnect the radiator and heater hose from manifold.
- Disconnect the throttle linkage and fuel line.
- Disconnect the coil wires and temperature sending unit.
- Disconnect the power brake hose, distributor vacuum hose, and crankcase vent hoses.
- Remove the distributor making sure to matchmark the rotor-to-housing and housing-to-engine block positions so that they can be matched during installation.
- Remove the alternator upper bracket and the coil and bracket.
- Remove the manifold attaching bolts.
- Remove the intake manifold and carburetor.
- Remove the rocker arm covers.
- Loosen and remove the rocker arm nuts, balls, rocker arms, and pushrods. These items must be replaced in their original locations.
- Remove cylinder head bolts, cylinder head, and gaskets.
- Reverse procedure to install. Tighten head bolts evenly to the specified torque. On engines having steel gasket, use sealer on both sides. No sealer should be used on steel-asbestos gaskets. Adjust the valve lash.
- Drain the cooling system.
- Remove the intake manifold and carburetor as an assembly.
- Remove exhaust manifolds.
- Loosen or remove any accessory brackets which interfere.
- Remove the valve cover. Loosen any accessory brackets which are in the way.
- Remove the battery ground strap from the cylinder head.
- Remove rocker arm bolts, pivots, rocker arms and pushrods. Scribe the pivots and identify the rocker arms and pushrods so that they may be installed in their original locations.
On cars with the 455 engine and air-conditioning, it may be necessary to disconnect the right motor mount and jack up the right front corner of the engine to remove the number eight pushrod. If the car is equipped with power brakes, it may be necessary to disconnect the booster and turn it sideways to remove the number seven pushrod.
- Remove cylinder head bolts and cylinder head(s).
- Install in the reverse order of removal. It is recommended that the head gasket be coated on both sides with sealer. Dip head bolts in oil before installing.
- Tighten all head bolts in the correct sequence to 60-70 ft. lbs. (81-95 Nm), then again is sequence to the specified torque.
- See Specifications at the beginning of this section for correct head bolt torque. Retorque the bolts after engine is warmed up.
In 1981 and later models the head gaskets must be installed without sealer.
See diesel valve lifter bleed down procedure.
- Remove the intake manifold, using the procedure outlined above.
- Remove the rocker arm cover(s), after removing any accessory brackets which interfere with cover removal.
- Disconnect and label the flow plug wiring.
- If the right cylinder head is being removed, remove the ground strap from the head.
- Remove the rocker arm bolts, the bridged pivots, the rocker arms, and the pushrods, keeping all the parts in order so that they can be returned to their original positions. It is a good practice to number or mark the parts to avoid interchanging them.
- Remove the fuel return lines from the nozzles.
- Remove the exhaust manifold(s), using the procedure outlines above.
- Remove the engine block drain plug on the side of the engine from which the cylinder head is being removed. On V6's, remove the pipe-thread plugs covering the upper cylinder head bolts.
- Remove the head bolts. Remove the cylinder head.
- First clean the mating surfaces thoroughly. Install new head gaskets on the engine block. Do not coat the gaskets with any sealer. The gaskets have a special coating that eliminates the need for sealer. The use of sealer will interfere with this coating and cause leaks. Install cylinder head onto the block.
- Clean the had bolts (and pipe-thread plugs) thoroughly. On the V8, dip the bolts in clean engine oil and install into the cylinder head until the heads of the bolts lightly contact the cylinder block. On V6's, coat the plug threads, bolt threads and the area under the bolt threads with sealer/lubricant part No. 1052080 or equivalent.
The correct sealer must be used or coolant leaks and bolt torque loss will result.
- On the V8, tighten the bolts, in the sequence illustrated, to 100 ft. lbs. When all bolts have been tightened to this figure, begin the tightening sequence again, and torque all bolts to 130 ft. lbs.
- On V6's, tighten all head bolts in sequence to the following torques:
- All except bolts 5, 6, 11, 12, 13 and 14 - 100 ft. lbs.(19-135.5 Nm)
- Bolts 5, 6, 11, 12, 13, and 14 - 41 ft. lbs. (19-55.5 Nm)
- All bolts except 5, 6, 11, 12, 13, and 14 - 142 ft. lbs. (19-192.5 Nm)
- Bolts 5, 6, 11, 12, 13, and 14 - 59 ft. lbs. (19-80 Nm)
CLEANING AND INSPECTION
See Figures 13, 14, 15 and 16
Chip carbon away from the valve heads, combustion chambers, and ports, using a chisel made of hardwood. Remove the remaining deposits with a stiff wire brush fitted to an electric drill.
Be sure that the deposits are actually removed, rather than burnished. Have the cylinder head (cast iron only) hot-tanked to remove grease, corrosions, and scale from the water passages.
See Figures 17 and 18
Cylinder head resurfacing should be performed by a competent machine shop.
Place a straight-edge across the gasket surface of the cylinder head. Using feeler gauges, determine the clearance at the center of the straightedge. If warpage exceeds 0.003 in. (0.076mm) in a 6 in. (152mm) span, or 0.006 in. (0.152mm) over the total length, the cylinder head must be resurfaced.
If warpage exceeds the manufacturer's maximum tolerance for material removal, the cylinder head must be replaced.
When milling the cylinder heads of V-type engines, the intake manifold mounting position is altered, and must be corrected by milling the manifold flange a proportionate amount.