Holden Commodore (VB-VL), Frequently Asked Questions

What engines were available in the VB-VL Commodore?

The VB-VK models used Holden’s own engines: the 3.3-litre (202 cubic inch) inline six and the 4.2-litre (253) and 5.0-litre (308) V8s. These are all pushrod, overhead-valve, iron-block engines that trace their lineage back to the 1960s.

The VL broke from tradition entirely. It used Nissan RB30 engines, a 3.0-litre inline-six available in naturally aspirated (RB30E, 116 kW) and turbocharged (RB30ET, 150 kW) forms. The 5.0-litre Holden 308 V8 was also retained for the VL as an option.

Why did the VL use a Nissan engine?

General Motors directed Holden to source a modern engine rather than develop a new one in-house. The Holden 202 six was aging and didn’t meet tightening emissions and fuel economy standards. Nissan could supply the RB30 at competitive cost, and it was a genuinely modern engine, overhead cam, electronic fuel injection, and available with turbocharging. The decision was economic and practical, but it caused enormous public backlash. An Australian car with a Japanese engine was seen as a betrayal by loyalists. History has vindicated the decision, the RB30 turbo became one of the most celebrated engines in Australian performance car culture.

What is the VL Walkinshaw?

The VL Walkinshaw, officially the HSV VL SS Group A SV, was a limited-production homologation special built by Tom Walkinshaw Racing (TWR) for Holden Special Vehicles (HSV). Only 750 were produced in 1988. It featured a larger T04B turbo, upgraded intercooler, revised ECU, Getrag 5-speed manual, Bilstein suspension, Recaro seats, and an aggressive body kit with a large rear wing. It produced 204 kW from the factory and was built to homologate the VL for Group A touring car racing. Today, the Walkinshaw is one of Australia’s most valuable and collectible muscle cars, with verified examples commanding $200,000-500,000+.

What is an HDT Commodore?

HDT stands for Holden Dealer Team, Peter Brock’s motorsport and performance car operation. From the VH through to the VL, HDT offered a range of dealer-installed performance and cosmetic upgrades for Commodores. These ranged from the entry-level “Director” package (body kit, decals, interior upgrades, primarily cosmetic) through to the full “Group Three” and “Group A” homologation specials with serious mechanical upgrades. HDT Commodores were sold through Holden dealerships with their own build plates. Genuine HDT cars are highly collectible, but be warned, fakes exist. The HDT Owners Club maintains a registry that can verify a car’s authenticity using the build plate number.

Is the VL turbo head gasket really that bad?

Yes. The factory composite head gasket on the RB30ET is the engine’s single biggest weakness. It’s adequate at the stock 7 psi boost level in a well-maintained engine, but it’s marginal. Increase the boost even slightly, or if the engine has ever overheated, and the gasket will fail. Symptoms include overheating, white exhaust smoke, coolant loss, and milky residue in the oil.

The fix is an upgrade to a multi-layer steel (MLS) head gasket, ideally with ARP head studs. This is a $800-1,500 job and should be considered essential maintenance on any VL turbo, even if the current gasket appears fine. Every experienced VL turbo owner will tell you the same thing: do the head gasket before it does you.

How much power can a stock RB30 turbo handle?

The stock RB30ET bottom end (block, crank, rods, pistons) is good to approximately 250-280 kW at the flywheel with proper supporting modifications (upgraded head gasket, better turbo, fuel system, intercooler, and tune). Beyond that, the factory cast pistons become the weak point, they can crack under sustained high boost.

For serious power (300+ kW), most builders step up to forged pistons and stronger connecting rods. The RB30 block itself is extremely strong, it’s essentially a destroked RB engine with a robust bottom end. Some builds have achieved 400+ kW on an RB30 bottom end with forged internals.

The factory Garrett T3 turbo is the first bottleneck. It runs out of puff at around 180-200 kW at the flywheel. Upgrading to a T3/T4 hybrid or larger aftermarket turbo is the most common first step for serious power.

Can I fit an RB30 turbo engine into a VB-VK Commodore?

It’s been done, but it’s not a simple swap. The VB-VK engine bay was designed for the Holden six and V8, and the RB30 has a completely different bellhousing pattern, wiring loom, and engine management system. You’ll need custom engine mounts, a custom or adapted gearbox bellhousing, a wiring loom, and an ECU. Most builders who want turbo power in a VB-VK opt for a turbo conversion on the existing 308 V8 or a Holden-based supercharger setup instead.

The easier path for turbocharged six-cylinder power in an earlier Commodore is to buy a VL and enjoy the factory integration.

What’s the difference between the 253 and 308 V8?

Both are part of the Holden V8 family, same basic architecture, same bolt pattern, largely interchangeable components. The 253 (4.2L) has a smaller bore and produces less power, typically 92-100 kW from the factory. The 308 (5.0L) has the larger bore and produces 108-136 kW depending on the model and state of tune.

The 308 is the one you want. It has significantly more low-end torque, responds better to modifications, and has a much larger aftermarket. The 253 can be built into a strong engine (many racers bore and stroke them to 308 or larger), but if you’re buying a car, just get the 308.

How bad is the rust problem?

It’s the single biggest issue with VB-VL ownership. These cars are 38-48 years old and many have spent their lives in coastal or high-humidity environments. The critical areas are the sills (rocker panels), wheel arches, boot floor, lower doors, and windscreen surrounds.

Sill rust is the deal-breaker. The sills are a structural part of the unibody, if they’re perforated, the car’s body loses rigidity. Repair is expensive ($2,000-5,000 per side) and requires skilled panel work. Never buy a VB-VL without getting under it with a torch and poking the sills with a screwdriver.

A car that’s spent its life in a dry inland climate (central Queensland, outback NSW, South Australia) will be in far better shape than one from Melbourne, Sydney’s coastal suburbs, or Tasmania.

What’s the best VB-VL to buy as a first classic car?

A VL with the naturally aspirated RB30E six and a manual gearbox is probably the smartest entry point. The RB30E is mechanically simple, parts are available, fuel injection means it starts and runs reliably, and the car has the best-developed suspension of the VB-VL range. They’re still relatively affordable ($5,000-15,000 for a decent example) and they drive well.

If you want a V8, a VH or VK with the 308 and a manual is the pick. The VH/VK has more interior space and refinement than the VB/VC, and the 308 is a brilliant engine to learn on.

Avoid the VL turbo as a first classic car unless you’re mechanically experienced. The turbo adds complexity, the engines need careful maintenance, and the temptation to increase boost leads down an expensive rabbit hole.

Are VB-VK manual gearboxes hard to find?

Yes. The vast majority of VB-VK Commodores sold in Australia were automatics. Manual V8 models are particularly scarce and command a significant premium. The Borg Warner T5 5-speed (fitted to later VK models) is the most desirable manual option. Earlier VB-VH V8 manuals used a Saginaw 4-speed.

For the VL, manual turbo models are also the minority but are more attainable than manual VB-VK V8s. The VL Getrag 5-speed is a strong, well-regarded gearbox.

If you’re buying a car with the intention of manual conversion, the VL is the easier swap, VL manual conversion kits and components are well documented. VB-VK manual conversions require more work, particularly for the V8 models.

What fuel should I use?

VB-VK carburettor models: 91 RON unleaded. These engines were designed for leaded fuel, but all have been running on unleaded for decades without issues (the valve seats are hardened).

VL RB30E (naturally aspirated): 91 RON unleaded.

VL RB30ET (turbo): 95 or 98 RON recommended. The higher octane rating reduces the risk of detonation (knock) under boost, which protects the head gasket and engine internals. If you’re running any boost above stock levels, 98 RON is essential.

VB-VK 308 V8: 91 RON for carburettor models. Higher-compression or modified engines benefit from 95 RON.

Avoid E10 on all models, the ethanol attacks old rubber fuel lines, seals, and carburettor components.

Where do I find parts?

Holden six and V8 parts (VB-VK): Wreckers are still the best source for body and trim parts. Rare Spares carries a wide range of reproduction and NOS parts for the Holden six and V8. Repco and Supercheap Auto stock common service items. For performance parts, Yella Terra, Crow Cams, Pacemaker, and Edelbrock all support the 308 V8.

RB30 parts (VL): The RB30 shares some components with the Nissan Skyline R31 and some Patrol models. Nissan wreckers are a useful source. Turbo-specific parts (injectors, turbos, intercoolers, ECU components) are available from aftermarket suppliers and the VL turbo community. RB30.com and various Facebook groups are active trading communities.

Body panels: The biggest challenge. NOS panels are almost gone. Reproduction panels are available for high-demand items (guards, boot floors, sill sections) from companies like Rare Spares. Quality varies. Good secondhand panels from dry-climate cars are worth their weight in gold, buy them when you find them.

How do I verify an HDT or Group A car is genuine?

Contact the HDT Owners Club of Australia. They maintain a registry of all genuine HDT-built vehicles, cross-referenced against factory build records. Every genuine HDT car has a unique build plate with a serial number that can be verified. The club can confirm whether a specific car is in their registry and whether the build plate matches the car’s VIN.

Be extremely cautious of cars advertised as HDT without documentation. HDT body kits, decals, and interior parts are available in the aftermarket, and it’s not difficult to make a standard Commodore look like an HDT car. The build plate is the only definitive proof. If the seller can’t provide HDT documentation or allow verification through the registry, walk away.

The same applies to the VK Group A and VL Walkinshaw. These cars have specific VIN ranges and production records that can be verified. Given the values involved ($200,000+), professional authentication is money well spent.

Is the VB-VL Commodore a good investment?

The market has been rising steadily for a decade. Clean V8 models, turbo VLs, and especially homologation specials (VK Group A, VL Walkinshaw, HDT editions) have appreciated significantly. The VB-VL represents the first generation of one of Australia’s most iconic car lines, and as these cars become scarcer through rust, accidents, and neglect, values for good examples will continue to climb.

The best investments are numbers-matching, documented, original-condition cars. Modified cars, even well-modified ones, rarely achieve the same values as factory-original examples. If you’re buying for investment, prioritise provenance and originality. If you’re buying to enjoy, buy the variant you actually want to drive and don’t worry about investment returns.