A ENGINE CYLINDER HEADS CASTING NUMBER:


There are basically only two different cylinder heads that have been used on the "LA" engines from 1964-1984 a small port 273-318 and a big port 340-360. There have been only three different valve combinations in these heads: one for the 273 and 318 with 1.78" intake and 1.50" exhaust; one for the 1968-1971 340 with 2.02" intake and 1.60" exhaust; and one for the 360 and the 1972-1973 340 with 1.88" intake and 1.60" exhaust.

 

Engine

 

Year

 

Casting Number

Valve Sizes (in.)

In.

Valve Sizes (in.)

Ex.

Combustio-Chamber Volume (cc)

 

Rocker-Arm Type
273 64-65 2465315 1.78 1.50 57 Adjustable**
273 66 2536178 1.78 1.50 57 Adjustable**
273 67 2658920 1.78 1.50 57 Adjustable**
273 68-69 2843675 1.78 1.50 60 Non-Adjustable
318 67 2658920 1.78 1.50 57 Non-Adjustable
318* 67 2658234 1.78 1.50 57 Non-Adjustable
318 68-71 2843675 1.78 1.50 60 Non-Adjustable
318 72 2843675 1.78 a1.50 60 Non-Adjustable
318 73-74 2843675 1.78 1.50 60 Non-Adjustable
318 75-76 3769973 1.78 1.50 63 Non-Adjustable
318 77-80 4027163 1.78 1.50 63 Non-Adjustable
318 77-80 4027593 1.78 1.50 63 Non-Adjustable
340 68-71 2531894 2.02 1.60 63 Non-Adjustable
340TA 70 3418915 2.02 1.60 65 Adjustable**
340 72 3671587 1.88 1.60 65 Non-Adjustable
340 73 3671587 1.88 1.60 65 Non-Adjustable
360 71 3418915 1.88 1.60 65 Non-Adjustable
360 71 3418915 1.88 1.60 65 Non-Adjustable
360 73-74 3671587 1.88 1.60 65 Non-Adjustable
360 75 3769974 1.88 1.60 65 Non-Adjustable
360 76 3769974 1.88 1.60 65 Non-Adjustable
360 76 3671587 1.88 1.60 65 Non-Adjustable
360 77-80 4027596 1.88 1.60 66 Non-Adjustable

360

 77-80 4071051 1.88 1.60 66 Non-Adjustable

Each casting can be machined differently, so use casting numbers as a guideline only. Use the physical features of the part for final identification.

*Used only on 1967 trucks with water-heated intake manifolds. This head will interchange with other 318 heads only if water-heated intake manifold is used.
**Uses cast rocker arms with adjustment screws and locknuts. Intake rocker arms are offset left or right. Early 273 uses straight rockers locked with interference-fit screws.

ROD INDENTIFCATION:

Year Engine Pin Type Part Number

Forging Number

 Crank-Journal Diameter (in.) Bearring-Bore Diameter (in.) Center-to-Center Length (in.) Rod Offset (in.) Wrist-pin Diameter (in.)
64-71 273/318 Floating 2406785 1618699 2.1245 2.2500 6.123 0.0486 0.9842
72-73 318 Floating 2899495 2899496 2.1245 2.2505 6.123 0.100 0.9842
74-80 318 Pressed 2899061 3418645 2.1245 2.2505 6.123 None 0.9480
68-73 340 Floating 2899495 2899496 2.1245 2.2505 6.123 0.100 0.9842
71-80 360 Pressed 2899061 3418645 2.1245 2.2505 6.123 None 0.9480

CRANK SPECIFICATIONS:

Year CID Crank Material Rod Style Forging or Casting Number Stroke Main-Journal Diameter Rod-Journal Diameter
64-67 273 Forged Steel Light-duty 2128278 2128869 2205700 3.31 in. 2.50 in. 2.125 in.
68-69 273 Cast Iron Light-duty 2658278 2658393 3.31 in 2.50 in 2.125 in.
67-73 318 Cast Iron Light-duty 2658278 2658393 3.31 in 2.50 in 2.125 in.
74-80 318 Cast Iron Heavy-duty 2658278 2658393 3.31 in 2.50 in 2.125 in.
68-72 340 Forged Steel Heavy-duty 2532457 2843868 3.31 in 2.50 in 2.125 in.
73 340 Cast Iron* Heavy-duty 3462387 3.31 in 2.50 in 2.125 in.
71-80 360 Cast Iron** Heavy-duty 3418640 3418641 3418642 3.58 in. 2.81 in. 2.125 in.

*73 340 cast cranks are shot peened.
**74-75 360 4-barrel cranks are shot peened.
Important crank feature: Manual transmission cranks have pilot-bushing bores of 15/16 in. Smaller automatic-transmission pilot bores
will not accept manual-transmission pilot bushings.
Forged cranks can be identified by the 3/8-1 /2 in.-wide forging flash. Cast cranks can be identified by the 1 /4 in.-wide casting flash.


DAMPER IDENTIFICATION AND CASTING NUMBERS:

Year CID Crank Type Casting Number Bolt Pattern
65-68 273 Forged 1947235 Offset
69-71 318 Cast 2951673 Offset
72-73 318 Cast 3614369 Symmetrical
74-80 318 Cast 4095633 Symmetrical
68-71 340 Forged 2951673 Offset
72 340 Forged 3614369 Symmetrical
72-73 340 Cast 3751160 Symmetrical
71 360 Cast 3512972 Offset
72 360 Cast 3614370 Symmetrical
73-77 360 Cast 3751808 Symmetrical
78-80 360 Cast 4173447 Symmetrical
78-80 360 Cast 4095632 Symmetrical

Model years 64-71 use offset bolt pattern to retain damper pulley.

Model years 72-80 use symmetrical bolt pattern to retain damper pulley.

FLYWHEEL SPECIFICATIONS:

Year Engine Size Part number Balance
64-67 273 9.5 in. 2463256 Neutrel
67-80 318 10.5 in. 2264597 Neutrel
68-71 340 10.5 in. 2264597 Neutrel
72-73 340 10.5 in. 3681639 Detroit
71-80 360 10.5 in. 3410916 Detroit

Neutral Balance-Crankshaft, damper and flywheel or flexplate are each individually balanced, allowing for the separate use and mixing of the components.
Detroit Balance-Crankshaft, damper and flywheel or flexplate are balanced together. If the interchange of these parts becomes necessary, that part must be balanced to the other two.
All Chrysler flywheels are cast iron.

A-ENGINE OIL FLOW:

The oil passage to the oil filter at the side of the block is a drilled hole. The output oil to the filter and the return oil from the filter are separated from each other by a pressed-in plug, PN 3462871. Be sure this plug is pressed into the predrilled hole until it bottoms solidly.

RIGHT ANGLE OIL FILTER ADAPTER:

 

Small Chrysler

273, 318, 340, 360 A Engines

Firing Order

Cylinder Numbering Distributor Rotation

Rotor Under Cap Spins:

Clockwise

Torque Specs

always torque bolts in three equal increments

Bolts or Parts Lube or Sealer Torque to:
Main Caps Engine Oil 85 ft-lbs.
Connecting Rods (Plain) Engine Oil 45 ft-lbs.

Cylinder Heads

     273-318

     340-360

Engine oil

(blind hole)

Sealer

(water jacket)

 

85 ft-lbs.

95 ft-lbs.
Rocker Shaft brackets Engine Oil 17 ft-lbs.
Oil Pump Cover Engine Oil 95 in-lbs.
Oil Pump Engine Oil 35 ft-lbs.
Oil Pan Engine Oil 15 ft-lbs.
Camshaft Locking Bolt Thread Locker 35 ft-lbs.
Front Cover Engine Oil 30 ft-lbs.

Intake Manifold

(Cast Iron Heads)

 Non- Hardening Sealer 35 ft-lbs.
Valve Cover Engine Oil 6 ft-lbs.
Water Pump Non- Hardening Sealer 30 ft-lbs.
Fuel Pump Engine Oil 30 ft-lbs.
Starter mounting Bolts Engine Oil 50 ft-lbs.
Exhaust Manifold Anti-Seize Lubricant 30 ft-lbs.
Spark Plugs No Lube or Sealer 20 ft-lbs.

Flexplate/Flywheel

Thread Locker 55 ft-lbs.
Clutch Housing Bolts Engine Oil 30 ft-lbs.
Flexplate to Torque Converter Thread Locker 270 in-lbs.

Centerbolt

(Harmonic Damper)

 Engine Oil 135 ft-lbs.

Bellhousing

(Transmission to Block)

 Engine Oil 50 ft-lbs.