4L80E Swap: What It Takes Behind an LS
A 4L80E behind an LS needs five things: a computer that can run it, a driveshaft with a 32-spline yoke, a crossmember made for it, a cooler, and a tunnel big enough for the case. Plan on about $1,900 for a rebuilt unit and roughly $1,000 more in supporting parts.
What you need
| Part | Why | Est. cost |
|---|---|---|
| Rebuilt 4L80E | About 32 inches long and 175 lb. GM rated it at 440 lb-ft; healthy units are commonly run harder. | $1,900 |
| Computer that controls it | A matching Gen III/IV truck PCM with the right tune, or a Holley Terminator X Max. The base Terminator X can't run a 4L80E. | Varies |
| Driveshaft with 32-spline yoke | The 4L80E is longer than most transmissions it replaces, and its output takes a 32-spline yoke (same as a TH400). | $450 |
| Transmission crossmember | The mount sits in a different spot. Swap crossmembers are made per transmission. | $250 |
| Cooler and lines | The 4L80E makes a lot of heat. Use a cooler bigger than the radiator's built-in one. | $120 |
| Flexplate, converter bolts, crank spacer | Sets the converter at the right depth. | $120 |
| Speedometer fix | Cable-speedo cars need a cable drive such as the Dakota Digital ECD-100; electronic gauges need a signal calibrator. | $190–250 |
| Higher-stall converter (recommended with a cam) | Bigger cams and boost want roughly 3,000 rpm or more of stall. | $600 |
Will it fit your car?
Trucks, G-bodies, A-bodies and first- through third-gen F-bodies take a 4L80E; G-bodies need the case ears trimmed. The calculator flags it as too big without cutting in: 1982–2004 S-10 / Sonoma, 1984–96 Corvette, 1979–93 Fox body Mustang, 1989–98 Nissan 240SX, 1990–2005 Mazda Miata, 1993–2002 Mazda RX-7, 1992–99 BMW 3 Series, 1999–2006 BMW 3 Series. In those, most swaps use a 4L60E/4L65E or a T56/TR6060.
How to tell a 4L80E from a 4L60E at the yard
The 4L80E's main electrical connector is horizontal on the driver's side. The 4L60E's is vertical on the passenger side.
4L80E vs the alternatives
| Transmission | Torque (calculator figure) | Typical cost |
|---|---|---|
| 4L60E (rebuilt) | ~360 lb-ft | $1,400 |
| 4L65E (rebuilt) | ~380 lb-ft | $1,800 |
| 4L80E (rebuilt) | ~600 lb-ft (commonly run; GM rated 440) | $1,900 |
| 6L80E | ~440 lb-ft | $2,400 |
| Built TH400 (3-speed auto) | ~1000 lb-ft (built, commonly run) | $2,600 |
| T56 6-speed manual | ~450 lb-ft | $2,900 |
| TR6060 6-speed manual | ~590 lb-ft (430–650 depending on version) | $3,900 |
| Tremec T56 Magnum 6-speed | ~700 lb-ft | $4,400 |
See a 4L80E build with every part
Sources
- PSI Conversion: 4L60E and 4L80E transmission guide for LS swaps
- PSI Conversion: Holley Terminator X harnesses
- Denny's Driveshafts: 32-spline slip yoke (TH400, 4L80E)
- Chevy Hardcore: Dakota Digital ECD-100
- GBodyForum: G-body LS swap info
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