SKU: TRETUET11012
MPN: TUET11012
The TREMEC T56 Magnum (TUET11012) is a 6-speed manual transmission built for GM LS-series engines in high-horsepower builds. It's the gearbox shooters and gearheads reach for when an LS swap, resto-mod, or pro-touring project needs a manual that won't quit behind serious torque. Rated to 700 lb-ft, this T56 transmission pairs supercar-derived synchro technology with double-overdrive gearing that keeps highway RPM low while still delivering short, deliberate throws. Whether the build is a street car, a road racer, or a weekend strip machine, the Magnum handles power that would shred lesser six-speeds. It's the modern standard for anyone running an LS and rowing their own gears.
Inside the aluminum case, the Magnum runs 4616 chromoly gears and shafts with a 26-spline input and 31-spline output. Gear ratios run 2.97, 2.10, 1.46, 1.00, 0.74, and 0.50, giving a deep first gear for launch and two overdrives for relaxed cruising. Triple-cone synchronizers on gears one through four and double-cone units on fifth, sixth, and reverse make for crisp, repeatable shifts under load. The transmission spins to a 7,800 RPM rating and carries 3.65 to 4 quarts of fluid, accepting Dexron III ATF, GM Synchromesh, or TREMEC HP-MTF. The OEM-grade die-cast aluminum shifter is reversible, and dual speedometer pickups cover both electronic and mechanical setups. Builders pairing this with a fresh clutch should check our flywheel and pressure plate stock.
This T56 Magnum fits LS conversions across muscle cars, trucks, and purpose-built track cars where a stout six-speed is non-negotiable. The 700 lb-ft rating leaves headroom for boost or nitrous, and the two overdrive gears make it just as livable on a long highway pull as it is hammering through a road course. Most installs call for a matched shifter location, a compatible clutch package, and a driveshaft yoke to finish the swap. Browse the rest of our drivetrain parts for the supporting hardware, and check our yoke selection to mate the output to your existing shaft.
TREMEC rates the T56 Magnum at 700 lb-ft of torque per manufacturer specifications. That capacity comes from 4616 chromoly gears and shafts in an aluminum case, leaving headroom for boosted or nitrous LS builds running well past stock output.
This version is built for GM LS-series engines, with a 26-spline input shaft and 31-spline output shaft. It's the wide-ratio configuration commonly used in LS swaps, resto-mods, and pro-touring builds where a six-speed manual is needed behind a GM small-block.
The gear ratios are 2.97 first, 2.10 second, 1.46 third, 1.00 fourth, 0.74 fifth, and 0.50 sixth. The deep first gear helps launch, while the two overdrive gears keep highway RPM low for comfortable cruising.
It holds 3.65 to 4 quarts and accepts Dexron III ATF, GM Synchromesh, or TREMEC HP-MTF. Use the fluid spec that matches your build and shifting feel preferences; all three are approved by the manufacturer for this transmission.
The Magnum weighs roughly 130 to 135 lbs dry, depending on the source. Shipping weight runs higher once crated and protected for transit. Plan your install and lift accordingly when mating it to an LS engine.
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