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5.3 vs 5.7 LS: what's the difference?
The 5.7 (LS1/LS6) was the Gen III car engine; the 5.3 (LM7 and relatives) was the truck engine. Both use the same 3.622 in stroke — the extra displacement comes from the bigger bore (3.898 in vs 3.78 in). Here's the most common of each:
Last updated
| LM7 | LS1 | |
|---|---|---|
| Family | Generation III | Generation III |
| Years | 1999–2007 | 1997–2005 |
| Displacement | 5.3 L (325 ci) | 5.7 L (346 ci) |
| Power | 270–295 hp | 295–382 hp |
| Torque | 315–335 lb-ft | 323–376 lb-ft |
| Bore × stroke | 3.78 × 3.622 in | 3.898 × 3.622 in |
| Compression | 9.49:1 | 10.25:1 |
| Block | iron | aluminum |
| AFM/DOD | no | no |
| VVT | no | no |
| Direct injection | no | no |
| VIN 8th digit | T | — |
Key differences:
- Bore: LM7 3.78 in, LS1 3.898 in
- Block: LM7 iron, LS1 aluminum
- Compression: LM7 9.49:1, LS1 10.25:1
For a swap: our donor table lists 55 vehicle applications for Gen III/IV 5.3 engines versus 19 for the 5.7 LS1/LS6 — mostly full-size trucks and SUVs for the 5.3, cars for the 5.7. Compare every option in the donor finder.
Specs are GM ratings as published; power varied by year and vehicle. Confirm any engine by the RPO code on the glovebox/console sticker.
Every Gen III/IV 5.3 and 5.7 side by side
- 5.3 L: 12 Gen III/IV engines; iron block: L59, LM7, LMF, LMG, LY5; aluminum: L33, LM4, LC9, LH6, LH8, LH9, LS4; AFM on the LC9, LH6, LMG, LS4, LY5; up to 320 hp from the factory.
- 5.7 L: 2 Gen III/IV engines; aluminum: LS1, LS6; none has AFM; up to 405 hp from the factory.
| RPO | Family | Years | Size | HP | Block | Compression | AFM | VVT | Crank |
|---|---|---|---|---|---|---|---|---|---|
| L33 | Gen III | 2005–2007 | 5.3 L | 310 | aluminum | 10.00:1 | No | No | 24x |
| L59 | Gen III | 2002–2007 | 5.3 L | 285–295 | iron | 9.50:1 | No | No | 24x |
| LM4 | Gen III | 2003–2005 | 5.3 L | 290 | aluminum | 9.50:1 | No | No | 24x |
| LM7 | Gen III | 1999–2007 | 5.3 L | 270–295 | iron | 9.49:1 | No | No | 24x |
| LS1 | Gen III | 1997–2005 | 5.7 L | 295–382 | aluminum | 10.25:1 | No | No | 24x |
| LS6 | Gen III | 2001–2005 | 5.7 L | 385–405 | aluminum | 10.50:1 | No | No | 24x |
| LC9 | Gen IV | 2007–2014 | 5.3 L | 315–320 | aluminum | 9.60:1 or 9.95:1 | Yes | Yes on some model years | 58x |
| LH6 | Gen IV | 2005–2009 | 5.3 L | 300–315 | aluminum | 9.95:1 | Yes | Not confirmed | 24x or 58x (by year) |
| LH8 | Gen IV | 2008–2009 | 5.3 L | 300 | aluminum | 9.90:1 | No | No | 58x |
| LH9 | Gen IV | 2010–2012 | 5.3 L | 300 | aluminum | 9.70:1 or 9.90:1 | No | Yes | 58x |
| LMF | Gen IV | 2008–2014 | 5.3 L | 315–320 | iron | 9.60:1 | No | Yes on some model years | 58x |
| LMG | Gen IV | 2007–2014 | 5.3 L | 315–320 | iron | 9.60:1 | Yes | Not confirmed | 58x |
| LS4 | Gen IV | 2005–2009 | 5.3 L | 300–303 | aluminum | 10.00:1 | Yes | No | 24x or 58x (by year) |
| LY5 | Gen IV | 2007–2009 | 5.3 L | 315–320 | iron | 9.95:1 | Yes | Not confirmed | 58x |
From our engine table: GM ratings as published, which varied by year and vehicle. Each RPO links to its page with donors, swap notes and real-tune ranges.