L59 5.3L engine: specs, donor vehicles & swap notes
The L59 is a 5.3 L iron-block Generation III engine built 2002–2007, rated 285–295 hp. It came in 4 vehicle applications, including Chevrolet Tahoe/GMC Yukon, Chevrolet Suburban/GMC Yukon XL 1500.
| Spec | Value |
|---|---|
| RPO | L59 |
| Family | Generation III |
| Years | 2002–2007 |
| Displacement | 5.3 L / 325 ci |
| Horsepower | 285–295 hp |
| Torque | 320–335 lb-ft |
| Bore × stroke | 3.78 × 3.622 in |
| Compression | 9.50:1 |
| Block | iron |
| AFM/DOD | No |
| VIN 8th digit | Z |
| Reluctor | 24x |
| Throttle | Cable 2002; drive-by-wire 2003-2007 |
| Stock cam | Duration 191°/190° @.050 in. int./exh.; valve lift 0.457"/0.466" int./exh.; 114° LSA; 3-bolt cam gear. |
| Firing order | 1-8-7-2-6-5-4-3 |
| Oil capacity | 6.0 qt |
| Spark plug | 12571164 / 41-985 |
| Plug gap | 0.040 in |
- Knock sensor corrosion (water intrusion under intake). Fix: Replace sensors and harness; seal valley; new intake gaskets.
- Oil consumption (rings / PCV). Fix: Monitor level; check PCV and valve seals; rings if excessive.
Iron/Alum. heads, E85-capable
The L59 specs above are not yet confirmed against GM documents; GM ratings varied by year and vehicle.
How the L59 differs from the other 5.3 L Gen III engines
The L59 is one of the four 5.3 L Gen III engines we list: L33, L59, LM4, LM7. From our engine table:
- Iron block. Among the 5.3 L Gen III engines, the L59 shares it with the LM7; the L33, LM4 are aluminum.
- Compression 9.50:1, within the group's 9.49–10:1 spread.
- Up to 295 hp from the factory (2nd of the four 5.3 L Gen III engines we list; the group tops out at 310 hp).
- Built E85-capable (flex fuel) from the factory. Swapping an L59 onto E85 still means wiring the flex sensor and setting up the tune for it.
- Built 2002–2007.
Swapping the L59: what to plan for
- Computer: 24x crank, so the L59 matches a Gen III computer (0411/P01 or P59); an E38 or E67 only reads 58x. Throttle and wiring have to suit the computer too. More: how to wire your LS (the full checklist for your engine and computer).
- Throttle depends on the year: Cable 2002; drive-by-wire 2003-2007. Drive-by-wire needs the matching pedal and throttle body; the base Holley Terminator X is cable-only (the X Max does drive-by-wire).
- From a truck or SUV (Chevrolet Avalanche 1500, Chevrolet Silverado/GMC Sierra 1500, Chevrolet Suburban/GMC Yukon XL 1500, Chevrolet Tahoe/GMC Yukon): truck accessory drive spacing (the farthest forward of the three), and the factory truck oil pan hangs low; most car swaps need a swap pan. More: accessory drive spacing · oil pans.
Refresh parts for the L59
From our Gen III refresh list, the parts that are specific to the L59. Seals, gaskets and the upgrades worth doing on any Gen III with the engine out are in the full refresh list, next to every torque spec.
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| Part | GM part # | Why for this engine |
|---|---|---|
| Stock cylinder head bolt set, 1997-2003 LS (unequal-length design) | 12498545 | L59 engines built through 2003 use the first-design, unequal-length bolts. Single use. Engines built from 2004 take the second-design, equal-length set (in the Gen IV list). |
| Chevrolet Performance Gen III LS knock sensor 12589867 (each) | 12589867 | The L59 has its knock sensors in the valley, under the intake, where water collects. |
| Chevrolet Performance LS Gen III camshaft position sensor 19420911 | 19420911 | 24x engines like the L59 read the cam at the rear of the block. |
From real tunes: 5.3 L on a Gen III computer
What these settings look like in the 472 naturally aspirated pump-gas tunes for 5.3 L engines on Gen III computers (0411/P01, P59) in our tune library (as of 2026-10-15). Every RPO of this size is pooled, not only the L59, and so are all cams, heads and builds: that is why the ranges are wide. Use them to spot a value that is far outside what works, not as your numbers.
| Setting | Range | Median | Tunes |
|---|---|---|---|
| Hot idle target | 525 rpm to 900 rpm | 698 rpm | 472 (middle 80%) |
| Warm idle airflow, in gear | 5.6 g/s to 12.7 g/s | 6.8 g/s | 471 (middle 80%) |
| Idle spark (around 800 rpm) | 18° to 25° | 18° | 472 (middle 80%) |
| Power enrichment (PE) lambda | 0.78 to 0.87 | 0.80 | 464 (middle 80%) |
| WOT spark at 5,000 rpm, about 0.9 g/cyl | 11.0° to 26.0° | 15.6° | 472 (middle 80%) |
For starting values matched to your L59's cam, injectors and fuel, use the turn-on tune builder. Always finish on a dyno, and read our safe tuning limits before any wide-open pass.
Donor vehicles with the L59
Where to find an L59 at the junkyard: 4 vehicle applications below. Confirm it from the RPO sticker in the glovebox or the 8th VIN digit (for the L59: Z).
| Vehicle | Years |
|---|---|
| Chevrolet Avalanche 1500 | 2005–2006 |
| Chevrolet Silverado/GMC Sierra 1500 | 2002–2007 |
| Chevrolet Suburban/GMC Yukon XL 1500 | 2002–2006 |
| Chevrolet Tahoe/GMC Yukon | 2002–2006 |
Buying a used L59
A used L59 has no single part number, so this page does not link a search. Confirm the engine from the RPO sticker or the 8th VIN digit (for the L59: Z) before you buy.