Poly 318 Engine Parts List

(Applicable to 277, 301, 303, 313, 318, 326, 390, 402 engines)

I have compiled a thorough parts list for the poly 318 and other A-block engines using brands I use and trust or for availability for items that have limited manufacturers. For interchange information, see the parts interchangeable page. For other brands, these part numbers should cross-reference. Many of these parts can be found at Summit Racing, JEGS, Speedway Motors, Rock Auto, Napa Auto Parts, and other retailers.


  • Cam: LA273/318/340/360, King or Clevite
  • Mains: LA273/318/340, King or Clevite
  • Rods: LA273/318/340/360, King or Clevite

Distributor: All LAs and Magnum 318/360 (see my ignition technical article for more details on selecting and timing the ignition system)

  • Recommended: Richard Ehrenberg’s USA-made “HiRev 7500” distributor, control unit, coil, and ballast resistor.
  • Note: Cheap units, such as Pertronix and Proform, are built with inferior Chinese components and often have reliability and performance issues for optimum performance and reliability including erratic and bouncing timing.
  • Note: 2000 – 2013 Mopar Performance distributors with the miniaturized Accel GM HEI internals are prone to erratic timing.

Distributor Gear: LA273/318/340/360

  • Comp Cams 420
  • Howards Cams 94415
  • Crower 76010

Distributor Intermediate Shaft Bushing: Melling M-63030B

Flexplate and Flywheel: 1962 onward A/LA273/318/forged-crank 340 confirmed neutral balanced

  • LA360 and cast-crank 340 flexplates and flywheels can either be neutral balanced or weighted to balance the rotating assembly, so neutral confirmation is required.

Freeze Plugs:

  • 1956 – 1961: Melling MEP14B (brass dish)
  • 1956 – 1961: Sealed Power 3811014 (steel dish)
  • 1962 – 1966: Melling MPE-613BR or Sealed Power 3818010 (brass cup with cam plug)
  • 1962 – 1966: Napa 567014 (brass cup without cam plug)


  • Full Set: FelPro FS7734PT2
  • Full Set: Best Gasket RS579G
  • Cylinder Head: FelPro 7734PT
  • Exhaust Collector: FelPro 9045
    • Confirm OEM diameter
  • Exhaust Manifold: FelPro MS9342B
  • Fuel Pump: FelPro 6579
  • Intake Manifold (superior fiber type): Best Gasket 18019 
  • Intake Manifold (steel, can leak depending on surface trueness): FelPro MS9344SH
  • Oil Pan: FelPro OS6566C2 or 1806
  • Thermostat Housing: FelPro 35063
  • Timing Cover Set: FelPro TCS65631 or TCS45284
  • Valve Covers: FelPro VS11828R or VS11828C
  • All other gaskets: LA273/318/340

Heater Bypass Hose: DAYCO 70476 for 3/4″ barbs


  • Solid: Melling JB2084 or Sealed Power AT2084
  • Hydraulic: Melling JB879
    • Note: LA lifters are the same diameter but are taller than A-block lifters and require shorter custom pushrods.

Oil Filter (canister):

  • Gasket: FelPro 70522
    • Warning: Don’t use the rubber gasket since they are prone to pushing out and leaking.
  • Filter: Wix 51076

Oil Filter (spin-on):

  • Adapter Plate to Block: FelPro 70522
    • Warning: Don’t use the rubber gasket since they are prone to pushing out and leaking.
  • Very Short Filter 3.79”: Wix 51085
  • Short Filter 4.338”: Wix 51068
  • Standard Filter 5.18” 1 qt.: Wix 51515
  • Long Filter 7” 2 qt: Wix 51773

Oil Pump:


  • Cast: Egge L2050
    • Note: Search ebay for the pistons since they are usually cheaper there than through Egge
  • Forged: Race Tec Pistons (California) for custom forged
  • Billet: Gibtec Pistons (Colorado) for custom billet

Piston Rings: Use LA318 for stock rebuilds. Refer to piston manufacturer for custom pistons.

  • Mahle 40069CP (Moly)
  • Mahle 50069CP (cast)
  • Mahle 41226 (chrome)

Pulley (Crank):

  • 1956 – 1992 A/LA
    • Note: 1970 – 1992 LA273/318/340 dampers and pulleys have a slightly different pulley bolt pattern, so using a 1970 – 1992 pulley on a pre-1970 damper or pre-1970 pulley on a later damper requires elongating pulley holes, which will not have a negative impact on anything.

Pulley (Water Pump):

  • 1956 – 1969 A/LA when using iron lefthand intake short-snout pump.
  • 1970 – 1992 LA when using aluminum righthand intake long-snout pump.

Pushrods: These are OEM lengths, but worn equipment on non-adjustable rocker arms or modified engines may require custom lengths and should be measured on all rebuilds.

  • Solid Lifter: MPR55 or Sealed Power RP3030 (5/16” x 8.418”)
  • Hydraulic Lifter: MPR153 (5/16” x 8.364”)

Rocker Arm Adjuster Screws (positive lock): 3/8″-24

Rocker Arm Shaft Expansion Plugs: Dorman 555-082 (45/64″) 

  • Note: The poly rocker arm shaft expansion plugs are larger than the LA shaft plugs, and the A-block plugs are not marketed through major distributors. I have researched and personally tried five different plugs, and the Dorman 555-082 is the best fit.

Spark Plug: 3/8” short-reach such as Autolite 85, Champion 63 (formerly J12Y), etc.

  • Warning: Do not install LA-type 3/4″ long-reach plugs, such as Autolite 65. They will contact the piston.
  • Note: There is a lot of misinformation about spark plugs with some people claiming A-block engines will only run well with one brand over the other, which is inaccurate. Any reputable brand spark plug will perform just fine with a healthy A/LA ignition system.

Starter Motor: see my article on available starter motors

Thermostat: (see my cooling system article for selection and discussion)

  • 180°: Stant 45358
  • 180° High-flow: Mr. Gasket 4363
  • 195°: Stant 45359
  • 195° High-flow: Mr. Gasket 4365
    • Note: High-flow thermostats should be paired with a high-flow water pump and larger radiator for optimal utilization.

Timing Set: LA273/318/340/360

  • Cloyes C3002K (OEM-type single non-roller)
  • Cloyes C3028X (double roller w/ cam advance adjustment)
  • Cloyes 93503X9 (billet double roller w/ cam advance adjustment)

Valve Cover Retainers:

  • Poly valve cover bolt cup washers: Skateboard truck washers are almost identical to the early A-block washers
  • Beck/Arnley 039-6659 (2003 – 2006 Honda Element EX 2.4L, info courtesy Michael Lindsay)
    • Note: These steel retainers are larger than the early 277/318 retainers but may be of interest to some.

Valve Springs: 1.70″ installed height springs for OEM machining.

  • Many LA springs are 1.7″ installed height.
  • Always follow the cam requirement for seat and open pressures at the cam’s maximum lift.

Valve Spring Keepers: 7° or 10° matched to valve stem diameter, groove type, and retainer angle.

Valve Spring Retainers: 7° or 10° degree matched to stem diameter, springs, and keepers.

Valve Stem Seals:

  • 3/8″ Stem Positive Seal: FelPro SS72730
  • 3/8″ Stem Umbrella: FelPro SS70014

Water Pump: 

  • Use 1957 – 1969 A/LA iron pump for factory left-side intake and short pump to match A-block pulleys (Figures 1 and 2).
    • OEM Type: WP58180, TFW43030 
    • High-flow: FlowKooler 1701
      • Note: Should use a high-flow thermostat for optimal utilization.
  • Use 1970 onward aluminum pump for right-side intake but will need 1970 onward pulleys since the pump is longer than the pre-1970 (Figures 1 and 2).
    • OEM Type: WP58181, TFW43026
    • High-flow model: Tuff Stuff 1465NA
      • Note: Should use a high-flow thermostat for optimal utilization.


Poly A-block 318 Pulleys Dodge Plymouth Chrysler Mopar
Figure 1: Pre-1970 A/LA Pulley (left) and Post-1969 LA Pulley (right)

Poly A-block 318 LA Short and Long Water Pumps Dodge Plymouth Chrysler Mopar
Figure 2: A-block Poly and LA Water Pumps