Poly 318 A-Block Torque Specifications

(also applicable to 277, 301, 303, 313, 318, and 326)

I have collected these poly A-block torque specs from a number of factory manuals and fastener data and added process notes from my experience and industry standards. These torque specifications work for all 1956 – 1966 A-blocks regardless of displacement. They assume a fastener grade 5 minimum.

Accessories Brackets:

  • 3/8” bolt: 30 ft.
  • 5/16” bolt: 25 lb.

Alternator/Generator Adjusting Bolt: 200 in.

Bellhousing Bolts: 50 ft.

  • Note: For automatics, ensure torque converter snout notches are fully aligned and engaged with the oil pump tangs before tightening bellhousing bolts. Failure to do so can result in broken bellhousing ears.

Camshaft Sprocket: 35 ft.

Camshaft Thrust Plate: 180 in. 

Carburetor Base to Intake: 60 – 80 in.

  • Note: Tighten evenly in an “X” pattern over three sequences. Overtightening can warp the baseplate and cause vacuum leaks.

Clutch Housing: 30 ft.

Connecting Rod Bolts: 45 ft.

Crankshaft End Bolt (harmonic balancer): 135 ft.

Cylinder Head Bolts: 85 ft.

  • See Figure 1 sequence below. Seal bolt threads. Tighten in three steps.

Distributor Hold-down: 180 in.

Exhaust Flange Nut/Bolt (7/16″-20): 40 lb.

Exhaust Manifolds: 25 ft.

  • See Figure 2 sequence below. Tighten in three steps. Recheck after multiple heat cycles.

Flexplate to Converter: 270 in.

Flexplate/Flywheel to Crank: 55 ft.

Flexplate/Flywheel/ Inspection Cover: 100 in.

Fuel Pump: 30 ft.

Intake Manifold: 30 ft. 

  • See Figure 3 sequence below. Tighten in three steps. Recheck after multiple heat cycles.

Main Caps: 85 ft. 

  • See Figure 4 sequence below. Tighten in three steps. 

Motor Mount

  • Block, 7/16-20, Grade 8: 40 ft.
  • To Chassis: 85 ft.

Oil Drain Plug: 25 ft.

Oil Pump Cover: 120 in.

Oil Pump Mounting Bolt: 35 ft.

Oil Pan: 180 in.

  • Work evenly from center out similar to Figure 3 below. Tighten in three steps.

Pulley (water pump and crank 5/16″ bolts): 200 in.

Rocker Arm Jam Nut: 25 ft.

Spark Plugs: 30 ft.

Starter Motor:

  • Stud nut or through-bolt: 25 ft.
  • Bolt or stud into aluminum: 216 in.

Timing Cover:

  • Iron: 35 ft.
  • Aluminum: 30 ft.

Thermostat Housing:

  • Iron Intake: 180 in.
  • Aluminum Intake: 144 in.

Valve Covers: 20 in. 

Water Pump: 30 ft.

Figures
Mopar A-block poly head torque sequence
Figure 1: Poly Cylinder Head Torque Sequence
Mopar A-block poly exhaust torque sequence
Figure 2: Poly Exhaust Torque Sequence (editor J. Lotspeich)
Mopar A-block poly intake torque sequence
Figure 3: Poly Intake Torque Sequence (editor J. Lotspeich)
Mopar A-block poly main cap torque sequence
Figure 4: Poly Main Cap Torque Sequence
Mopar A-block poly engine mount orientation
Figure 5: Correct Poly A-block and LA Motor Mount Bracket Position