4L80E swap behind an LS

The 4L80E is the heavy-duty GM 4-speed automatic, and it bolts to the LS: it uses the GM LS-family bellhousing pattern.

	4L60E (M30)	4L80E (MT1)
Torque rating	Stock ≈300–360 lb-ft (Speedway)	440 lb-ft; 4L85E (MN8) listed at 690 lb-ft*
Built for	~6,000 lb GVWR class (the "60")	Up to 18,000 lb GVWR depending on axle/vehicle
LS fit	LS bellhousing; LS versions use a 300 mm input shaft/LS converter	LS bellhousing

*A 2026 JEGS summary quoted 460 lb-ft for the 4L85E, so sources differ on that figure.

Controlling it: the 4L80E is electronically shifted, so it needs a computer:

• Factory GM truck PCM that was paired with a 4L80E, tuned for your combination, or
• Holley Terminator X Max, which has 4L60E/4L80E control built in.

When to pick it over a 4L60E: heavy vehicles, towing, and higher power, where the 4L60E's weak points (3–4 clutch pack, sun shell) show up. Compare every option in the transmission guide.