Holden Spare Parts

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engine-number

Holden Hd Engine Number

Years1965, 1966
SeriesHD
SubmodelsPremier, Special, Standard
Engines149 Petrol, 179 Petrol, X2 Petrol
Gear typesAutomatic, Manual
ChassisSedan, Ute, Van, Wagon
PartsVIN NumberEngine Number

Use this guide to locate the engine number on your Holden Hd and line up the right engine-related parts enquiry.

The Holden HD (1965-1966) is instantly recognised by its "kicked-up" rear quarter styling and the arrival of the high-output X2 twin-carburettor option, running Holden's red-motor sixes across sedan, wagon, ute and panel van bodies. It sat between the earlier EH and the facelifted HR that replaced it.

Where to find your Holden engine number

The stamped engine number is on a machined pad on the block. Its location depends on the engine family:

  • Inline six-cylinder: on a pad on the right-hand side of the block, above the engine-mount boss.
  • V8 (253 / 308, 4.2 / 5.0 litre): on a pad on the left-hand side of the block, above the engine mounting.
  • V6 (Buick-derived, Ecotec, Alloytec): on the front left-hand face of the block, below the ignition coil.
  • Later V6 and LS V8 models: the build / engine plate sits on the radiator support panel (VT-VZ era) or the passenger-side strut tower (VE / VF era).

You may need to wipe the pad clean to read the stamped number, and on air-conditioned cars the compressor can sit in front of it. Older Holden engines use a capacity-plus-tune prefix (for example 186S or a Q-series V8 code), while modern engines (Ecotec, Alloytec and the LS V8 family) use a GM engine code plus a separate stamped serial.

For the most accurate part match, send us both the engine code or prefix and the full stamped number, along with whether the car is automatic or manual.

On this model

The HD ran red-motor sixes: the 149 cubic-inch and the 179, with the twin-carburettor 179 X2 being the standout performance option that distinguishes an HD. The engine is identified by the prefix and number stamped on the block, so read and quote that stamping when ordering rather than assuming from the badge. The X2 differs mainly in its carburettion and tune rather than being a separate capacity, so verifying the actual engine fitted matters. Engine swaps are common on these cars after sixty years, so the block in the car may not be the original numbers-matching unit. If you are unsure of the exact prefix, provide the full stamped number and let the supplier match it rather than guessing.

Frequently asked questions

Where is the engine number on a Holden Hd?

It is stamped on a machined pad on the engine block. Inline sixes are on the right side above the engine mount, the 253/308 V8s on the left side above the mount, and the V6 engines on the front left face below the ignition coil. You may need to wipe the pad clean to read it.

What is the difference between an engine prefix and an engine code?

Older Holden engines use a capacity-plus-tune prefix stamped on the block, while modern engines (Ecotec, Alloytec and the LS V8 family) use a GM engine code plus a separate stamped serial.

Do you match engine numbers to parts?

Yes. Send us the engine code or prefix and the full stamped number, plus whether the car is automatic or manual, and we will match the right engine-related part.

Quick enquiry

Submit your Holden parts enquiry and we'll check availability.

We handle genuine, aftermarket, new and second-hand Holden parts enquiries.

Help us match the exact parts for your car. Complete at least one of the two sections below — your rego & state, or the full car details.

Option 1 Rego & state one of two required

Fastest — we look the car up from the plate.

Option 2 Exact car details one of two required

Best match if you have the build plate or VIN.

Availability will be checked before anything is quoted.

Holden Hd engine number — locate, decode and date your car

Checking a Holden Hd engine number is free. The number identifies the engine family and build, which is what confirms the right engine, cooling and ancillary parts. Find it, then send it with your parts enquiry and we will help you read it.

Where is the engine number on a Holden Hd?

It is stamped into a machined pad on the engine block — commonly near the front of the block, on the bellhousing flange, or beside a cylinder head. The exact spot depends on the engine family, so use the engine guidance above for the Hd and cross-check it against the build plate.

How do I look up or decode a Hd engine number?

The leading letters are the engine prefix (family and specification) and the digits are the build sequence. There is no public live lookup, so the fastest accurate decode is to send us the full prefix and number — we will identify the engine and the parts that suit it, free of charge.

What do the engine number prefix codes mean?

The prefix identifies the engine type, capacity and state of tune — it is how otherwise similar variants are told apart. Matching the prefix is what makes sure replacement parts actually fit.

Can the engine number tell me the year of my Hd?

On its own it indicates the engine family rather than a precise year. Read it alongside the VIN and build plate. Across the years the Hd was built 1965–1966, so the series and VIN pin down the exact build.