The HX Holden (1976–1977) is a really important model in Holden history, and from a restoration point of view it’s very different to HQ/HJ in ways that catch people out.
The HX Holden marked a major turning point for Australian Holdens. Introduced in mid-1976, the HX brought ADR27A emissions compliance, significant engine changes, new interior details, and subtle exterior updates. While it looks similar to earlier H-series cars, restoring an HX correctly requires HX-specific parts knowledge.
Whether you’re working on a Kingswood, Premier, Statesman, Sandman, One Tonner or Monaro GTS, this guide covers everything you need to restore an HX Holden properly — without wasting money on incorrect parts.
HX Holden Engines & Drivetrain
HX models are best known for their emissions-era engine changes, which directly affect parts availability and performance upgrades.
Factory Engine Options
- 173ci Red Motor
- 202ci Red Motor
- 253ci V8 (low compression)
- 308ci V8 (ADR27A compliant)
Important: HX engines use pollution gear and different cam profiles compared to HQ/HJ.
Engine Restoration Checklist
Six-Cylinder Engines (173 / 202)
- Pistons, rings & bearings
- ADR27A camshaft (or mild replacement)
- Timing chain & gears
- Oil pump
- Water pump
- Full gasket set
- Stromberg carburettor rebuild kit
- Intake & exhaust manifold gaskets
- Engine mounts (HX-specific)
V8 Engines (253 / 308)
- Low-compression pistons
- Camshaft compatible with ADR27A heads
- Timing set
- Oil pump
- Harmonic balancer
- Quadrajet carburettor rebuild kit
- Exhaust manifolds (HX-only in some cases)
Transmission & Differential (HX Holden)
Factory Gearboxes
- 3-speed manual
- 4-speed M20 / M21
- Trimatic automatic
- Turbo-Hydramatic 400 (308 V8)
Driveline Parts Checklist
- Clutch kit & spigot bush
- Gearbox rebuild kits
- Shifter bushes
- Tailshaft uni joints
- Differential bearings & seals
- Salisbury LSD centre (where fitted)
Fuel System & Cooling (HX-Specific)
HX Holdens run hotter than earlier models due to emissions tuning — cooling system condition is critical.
Fuel System
- Replacement fuel tank
- HX fuel sender unit
- Ethanol-safe fuel hose
- Mechanical fuel pump
- Charcoal canister hoses
Cooling System
- Radiator (HX-specific shroud design)
- Fan shroud
- Thermostat
- Heater core
- Correct emission-era hoses
Suspension, Steering & Brakes
Suspension
- Upper & lower control arm bushes
- Ball joints
- Coil springs
- Shock absorbers
- Rear trailing arm bushes
- Panhard rod bushes
Steering
- Steering box rebuild kit
- Tie rod ends
- Idler arm
- Rag joint
Brakes
- Front disc brake kits
- Rear drum rebuild kits
- Master cylinder
- Brake booster
- Brake hoses
Bodywork, Rust & Exterior Trim
Common HX Rust Areas
- Front chassis rails
- Floor pans
- Inner & outer sills
- Rear quarters
- Boot floor
- Plenum chamber
- Windscreen & rear window channels
- Lower front guards
Exterior Parts Checklist
- HX grille (unique insert style)
- Headlight surrounds
- Tail light lenses
- Bumpers
- Side mouldings
- HX badges & scripts
- Door handles
- Full rubber seal kits
Interior Restoration (HX Differences)
HX interiors differ again from HQ/HJ, especially in trim patterns and safety features.
Interior Checklist
- Seat frames & foam
- Correct HX seat trim
- Door cards (HX-only patterns)
- Dash pad
- Centre console
- Instrument cluster refurbishment
- Headlining
- Carpet kits
- Steering wheel restoration
Electrical System
Electrical Parts
- Wiring loom
- Headlight assemblies
- Tail lights
- Alternator upgrade
- Starter motor
- Voltage regulator
- Fuse box restoration
Wheels, Tyres & Finishing Touches
Wheels
- Steel wheels
- GTS wheels
- Period-correct alloys
Finishing Details
- Engine bay decals
- Correct fasteners
- Under-bonnet detailing kits
- Period accessories