LS1
The LS1 is the original LS engine. It was first produced in 1997 for the new C5 Corvette. It was available in GM cars from 1997 to 2004.
LS6
The LS6 is an improved version of the LS1. It was introduced in 2001 for the Z06 Corvette. The LS6 was available in the Corvette until 2004. It was also available in the 2004-05 Cadillac CTS-V.
For specific details about these engines, please follow the links below:
Benefits
- Power
- With tons of aftermarket options, they can make over 850 hp.
- Lightweight
-
- The engines weigh about 460 lbs. fully dressed with accessories and flexplate.
- Small Size
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- 24 in. (w) x 27 in. (l) x 27 in. (h)
What's the Difference?
The easiest way to tell the difference is to check the 8th digit of the VIN code.
- Follow this link to Identify an LS Engine by VIN.
Use the table below to identify the external differences between the 2 engines.
| RPO Code | Intake Manifold Design | Cylinder Head Casting Number | Exhaust Port Shape |
| LS1 | V-shaped bottom | 339, 592, 806, 853, 805, 621, 174, 241 | Oval |
| LS6 | Flat bottom | 243 | D-shaped |
Special Notes
- The LS6 "243" heads:
- Smaller chambers for increased compression
- Flow more air
- Hollow stem intake valves
- Sodium filled exhaust valves
- Higher valve spring pressure
- LS6 blocks were sand-cast and have windows in the bulkheads for better high-rpm breathing.
- LS6 cams had more lift and duration.
- LS6 pistons were cast with a stronger alloy.