L8B 5.3L engine: specs, donor vehicles & swap notes
The L8B is a 5.3 L aluminum-block Generation V engine built 2016–2018, rated 355 hp. It came in 1 vehicle application, including Chevrolet Silverado/GMC Sierra 1500 Hybrid. Things to know: it has AFM, so an aftermarket cam means a full AFM delete; it has variable valve timing; it is direct-injected (Gen V parts and controller).
We may earn a commission when you buy through links on this page.
| Spec | Value |
|---|---|
| RPO | L8B |
| Family | Generation V |
| Years | 2016–2018 |
| Displacement | 5.3 L / 325 ci |
| Horsepower | 355 hp |
| Torque | 383 lb-ft |
| Bore × stroke | 3.78 × 3.622 in |
| Compression | 11.00:1 |
| Block | aluminum |
| AFM/DOD | Yes |
| Reluctor | 58x |
| Throttle | Drive-by-wire |
| Stock cam | Cam PN 12619823; duration/lift/LSA not published; 1-bolt gear, 4x; AFM Yes, VVT Yes. |
| Firing order | 1-8-7-2-6-5-4-3 |
| Head casting | 12620214 |
- AFM lifter sticking/failure (ticking, misfire). Fix: Replace failed lifters; AFM delete/tune-out prevents recurrence.
- Direct-injection intake valve carbon buildup. Fix: Walnut-blast intake valves and ports; quality fuel and frequent oil changes slow buildup.
- AFM-related oil consumption. Fix: Check oil level regularly; AFM delete and correct-viscosity oil reduce consumption.
Aluminum, VVT, AFM, DI, E85-capable
The L8B specs above are not yet confirmed against GM documents; GM ratings varied by year and vehicle.
How the L8B differs from the other 5.3 L Gen V engines
The L8B is one of the four 5.3 L Gen V engines we list: L82, L83, L84, L8B. From our engine table:
- Compression 11.00:1, tied with the L82, L83, L84 for the lowest of the group.
- Up to 355 hp from the factory (2nd of the four 5.3 L Gen V engines we list; the group tops out at 376 hp).
- Variable valve timing. Also on the L82, L83, L84.
- Built E85-capable (flex fuel) from the factory. Swapping an L8B onto E85 still means wiring the flex sensor and setting up the tune for it.
- Built 2016–2018.
Swapping the L8B: what to plan for
- Computer: the L8B is a Gen V direct-injection engine, so it needs a Gen V computer or a Gen V-specific aftermarket kit; Gen III/IV harnesses and computers don't run it. More: LS swap ECU comparison.
- Drive-by-wire throttle: plan on the pedal and throttle body that match the L8B and its computer.
- AFM (cylinder deactivation): an aftermarket cam on the L8B means a delete kit made for Gen V engines, plus the tune.
Refresh parts for the L8B
From our Gen V refresh list, the parts that are specific to the L8B. Seals, gaskets and the upgrades worth doing on any Gen V with the engine out are in the full refresh list, next to every torque spec.
| Part | GM part # | Why for this engine |
|---|---|---|
| GM Gen V LT knock sensor 12623095 | 12623095 | Gen V knock sensor, as on the L8B. |
| GM Gen V LT camshaft position sensor 12623093 | 12623093 | Gen V cam sensor for the L8B. |
| GM Gen V LT crankshaft position sensor 12669636 | 12669636 | Gen V crank sensor for the L8B. |
| OEM-style LT Gen 5 cylinder head bolt kit | 11611976 | GM head bolts for Gen V engines like the L8B; check the part number for yours. |
Donor vehicles with the L8B
Where to find an L8B at the junkyard: 1 vehicle application below. Confirm it from the RPO sticker in the glovebox or the 8th VIN digit.
| Vehicle | Years |
|---|---|
| Chevrolet Silverado/GMC Sierra 1500 Hybrid | 2016–2018 |
Buying a used L8B
A used L8B 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 before you buy.