6.0 Vortec Specs: LQ4, LQ9, LY6 & L96 Horsepower, Torque and Differences

Short answer: The 6.0L Vortec is GM’s iron-block LS truck V8 (364 ci), and it came in several flavors. The LQ4 makes 300–325 hp, the high-output LQ9 bumps that to 345 hp, and the later Gen IV LY6 and L96 add variable valve timing for ~360–361 hp. All of them share the same tough iron block that made the 6.0 the go-to for towing, high-mileage work, and boosted LS builds.

6.0 Vortec specs at a glance

*The earliest 1999–2000 LQ4 used cast-iron cylinder heads; GM switched to aluminum heads after that.

Common specifications (all 6.0 Vortec)

• Displacement: 6.0 L / 364 ci
• Bore x stroke: 4.00 in x 3.62 in
• Block: cast iron (truck 6.0s) — the reason it takes boost and abuse so well
• Firing order: 1-8-7-2-6-5-4-3 (LS pattern)
• Family: GM LS-based small-block (Gen III / Gen IV)

LQ4 — the base 6.0 workhorse

The LQ4 (1999–2007) is the original 6.0 Vortec: 300–325 hp and 360–370 lb-ft depending on year and heads. It went in 2500/3500 trucks, big SUVs, and vans. It’s not the highest-output 6.0, but the iron block and truck-duty design make it a favorite starting point for cammed and boosted LS builds.

LQ9 — the high-output “VortecMAX”

The LQ9 (2002–2007) is the hot-rod 6.0: higher compression (flat-top pistons) for 345 hp and 380 lb-ft. GM used it in the Escalade, Silverado SS, and the VortecMAX package. If you want the strongest factory Gen III 6.0, this is it.

LY6 and L96 — the Gen IV 6.0s with VVT

The Gen IV trucks brought variable valve timing. The LY6 (2007–2010) makes about 361 hp and 385 lb-ft on regular 87 octane. The L96 (2010 and later) replaced it with roughly 360 hp / 380 lb-ft and E85 capability, and stuck around in HD trucks and vans for years. Both keep the iron block.

Is the 6.0 Vortec a good engine?

Yes — it’s one of the most respected truck V8s GM built. The iron block handles cam swaps, heads, and forced induction, parts are everywhere, and a well-maintained 6.0 routinely runs past 250,000 miles. It’s the reason the 6.0 is the darling of the LS swap world. Known items to watch are typical LS truck stuff: knock sensors in the valley (moisture intrusion), exhaust manifold bolt breakage with age, and hot-idle oil-pressure quirks on high-mileage units — see the hot-idle oil pressure guide.

Which 6.0 should you build?

• Strongest factory Gen III: LQ9 (345 hp).
• Cheapest iron-block core for boost: LQ4.
• Modern, VVT, E85: L96 / LY6.

For how the 6.0 stacks up against the other GMT800 engines, see the GMT800 engine guide, the 6.0 vs 8.1 comparison, and the 8.1L Vortec specs.

Frequently asked questions

Is the 6.0 Vortec an LS engine? Yes — it’s part of GM’s LS-based small-block family (Gen III and Gen IV), with an iron truck block.

How much horsepower does a 6.0 Vortec have? 300–325 hp (LQ4), 345 hp (LQ9), or ~360–361 hp (LY6/L96).

What’s the difference between LQ4 and LQ9? The LQ9 is the high-compression, high-output version — 345 hp vs the LQ4’s 300–325 hp.

Is the 6.0 good for towing? Yes — strong low-end torque and an iron block make it one of GM’s best gas towing engines short of the 8.1.

Discuss it

Running a 6.0? Post your RPO, year, mileage, and what you’ve done to it in the FullSizeChevy forum.

Sources: engine specifications per OnAllCylinders (Summit Racing) and the GM LS-based small-block reference. Verify exact figures against GM service information for your specific RPO and year.