FX-301

Holden HQ HJ HX HZ With LS 5.7-6.0L 1 7/8in Primaries 4 into 1 Tuned 3in Outlets

Holden HQ HJ HX HZ With LS 5.7-6.0L 1 7/8in Primaries 4 into 1 Tuned 3in Outlets Extractor (SKU: FX-301) Engineered.

BrandMantaMPI Automotive

Category: Extractors and headers

RRP $1494.15 AUD
In stock at supplier
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Holden HQ HJ HX HZ With LS 5.7-6.0L 1 7/8in Primaries 4 into 1 Tuned 3in Outlets Extractor product image

Part specs

SKU
FX-301
Supplier
MPI Automotive
Category
Extractors and headers
Vehicle fitment
Holden
Stock status
In stock at supplier

The MPI Automotive FX-301 is a tuned-length extractor listed to fit Holden HQ, HJ, HX and HZ models running an LS 5.7L or 6.0L engine. It uses 1-7/8in primaries in a 4-into-1 design with 3in outlets.

What does this extractor cover?

This is the header for an LS-swapped classic Holden — the FX-301 suits an HQ-HZ body with a 5.7L or 6.0L LS V8 fitted. It runs 1-7/8in primary tubes in a tuned 4-into-1 layout finishing in 3in outlets. The larger 1-7/8in primary is sized for the airflow of a modern LS rather than a stock engine, which is why this is a conversion part rather than a factory replacement.

What is a tuned-length extractor and what does it change?

A tuned-length (or equal-length) extractor sets each primary pipe to a deliberate length so the cylinders' exhaust pulses arrive at the collector in a chosen rhythm, rather than whatever the cast manifold happened to give. Merging 4-into-1 keeps all four runners on each bank feeding one collector. On an LS conversion into an HQ-HZ chassis, the extractor also bridges the gap between the modern engine's port layout and the older car's tunnel and steering — so geometry, not just tube size, is the work.

Will it suit my HQ-HZ Holden?

It's listed to fit the Holden HQ, HJ, HX and HZ bodies with an LS 5.7L or 6.0L. Because LS swaps vary in mounts, sump and steering, the exact build decides whether the 1-7/8in primaries clear everything — send us your conversion details and we'll confirm the FX-301 fits before ordering. We treat the listing as 'listed to fit', not guaranteed.

What does fitting involve at our Illawarra workshop?

Oak Flats Muffler Men supplies and fits LS-conversion extractors like the FX-301 across the Illawarra. We get the car up, check the primaries clear the steering and crossmember on your particular swap, and pipe the 3in outlets into the rest of the system. The RRP is listed at $1494.15, and we confirm the build with you first.

Stocked and fitted by Oak Flats Muffler Men, the Illawarra exhaust and 4x4 specialist in Oak Flats, NSW.

Common questions

Does the FX-301 suit an LS 5.7L and 6.0L?
Yes — it's listed for Holden HQ-HZ bodies running an LS 5.7L or 6.0L. Confirm your exact swap with the workshop before ordering.
What are the primary and outlet sizes?
It runs 1-7/8in primaries in a tuned 4-into-1 layout with 3in outlets, as listed.
Will it bolt straight into a standard HQ-HZ?
No — this is an LS-conversion extractor, not a part for the original engine. The fit depends on your conversion build, which we check first.

Fitment support across the Illawarra

Fitment checks near you across 18 Illawarra suburbs, from Oak Flats and Shellharbour to Wollongong and Kiama.
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Book the right exhaust job without guessing.

Send the vehicle make, model, year, engine, current issue, desired sound or performance goal, and clear photos of the existing exhaust where available.