Tremec TUET18132 Magnum XL T56 6-Speed Manual Transmission GM

TREMEC offers this GM-specific Magnum XL in a pair of ratio spreads built on the OEM TR-6060 platform originally developed for the Mustang; this TUET18132 unit is the 2.97 first-gear configuration, while a different spread exists separately for a closer-ratio build. Second gear falls to 2.10 and third to 1.46 ahead of fourth, which locks at 1.00; top gear lands at 0.63, and reverse comes in at 2.90. TREMEC rates the case for 700 lb-ft of torque with shifts to 7,800 rpm.

What the package includes

An SFI-rated steel bellhousing ships in the box, together with a crossmember, a mount for the transmission, and an isolated shifter paired with its own shift ball, so most of the GM-specific hardware needed to hang this case arrives already in the kit. The factory hydraulic clutch release carries over unchanged, so existing hydraulic parts can stay in place.

Why the shifter sits further back

An extended tail section stretches the case out and relocates the shift lever toward the rear of the cabin, using a stiff, directly mounted shifter rather than the floppier semi-remote linkage that many late-model factory transmissions rely on. Because this is a GM-chassis conversion rather than a factory-fit part, check your specific bellhousing bolt pattern and driveline fitment before ordering.

Does this include the bellhousing? Yes, an SFI-approved steel bellhousing ships with the kit, along with the crossmember and transmission mount.

Is this the only ratio spread TREMEC offers here? No, a closer-ratio GM Magnum XL spread exists separately; this listing is specifically the 2.97 first-gear configuration.