GSM (Gearbox Switch Module or Gear Selector Module) is used for electronic transmissions like 4L60E, 4L80E, 6L80E, or TR6060 when swapping an LS engine into a classic car.
Key features of a GSM unit:
| Feature | LS1 | LS2 | LS3 | |------------------------|----------------------------------|----------------------------------|----------------------------------| | Production years | 1997–2004 (Gen III) | 2005–2007 (Gen IV) | 2008–2013 (Gen IV) | | Displacement | 5.7L (346 ci) | 6.0L (364 ci) | 6.2L (376 ci) | | Horsepower (stock) | 305–350 hp | 400 hp | 430–436 hp | | Torque (stock) | 335–365 lb-ft | 400 lb-ft | 424–428 lb-ft | | Block material | Cast aluminum | Cast aluminum | Cast aluminum | | Heads | Cathedra ports (241/853/243/799)| 243/799 (cathedral) | Rectangular port (823/L92) | | Intake manifold | Composite (LS1 style) | Composite (LS2 style, taller) | Composite (LS3 style, high flow) | | Camshaft | .472/.472 lift, 199/207° @ .050 | .525/.525 lift, 204/211° @ .050 | .551/.551 lift, 204/211° @ .050 | | Connecting rods | Powdered metal | Powdered metal | Powdered metal (stronger) | | Pistons | Cast hypereutectic | Cast hypereutectic | Cast hypereutectic (improved) | | Crankshaft | Cast iron (reluctor: 24x) | Cast iron (reluctor: 24x or 58x) | Cast iron (reluctor: 58x) | | Redline | ~6000 rpm | ~6500 rpm | ~6600 rpm | | Common swaps into | Miata, RX-7, E36, S13 | Same as LS1 + heavier cars | Same + C6 Corvette, Camaro SS | | OEM applications | C5 Corvette, F-Body (Camaro/Firebird) | C6 Corvette (2005-2007), GTO, SSR, Trailblazer SS | C6 Corvette (2008-2013), 5th-gen Camaro SS, Holden | gsm ls1 ak ls2 ls3
This is your hardware. GSM is a brand renowned for heavy-duty transmissions and conversion kits. When you pair a GSM transmission (usually a 4L60E, 4L80E, or 6L80E) with an LS engine, you need specific controllers. The confusion arises because GSM makes plug-and-play harnesses that work across LS1, LS2, and LS3 engine generations, which have different crank trigger patterns and cam sensors. GSM (Gearbox Switch Module or Gear Selector Module)
In the world of automotive performance and custom fabrication, few strings of text generate as much confusion—and opportunity—as "gsm ls1 ak ls2 ls3". At first glance, this looks like a random sequence of engine codes and radio acronyms. However, for the seasoned tuner, restomod builder, or automotive electrician, this keyword represents a critical junction: integrating Global System for Mobile (GSM) communications, security, and telematics with the legendary General Motors LS family of engines (LS1, LS2, LS3) and the often-overlooked "AK" series controllers. | Feature | LS1 | LS2 | LS3
This article will dismantle each component, explore their interconnections, and provide a comprehensive guide to making these disparate technologies work in harmony.
Let’s walk through two realistic builds.