SBC 86-up Tremec T56 6 Speed Transmission Installation Kit, 700HP

The TREMEC T56 Magnum at the center of this installation kit carries a 700 lb-ft torque rating and shifts up to 7,800 RPM, with an included performance clutch assembly supporting engines producing up to roughly 800 horsepower. The kit targets 305 and 350 TBI or Vortec Small Block Chevy engines built from 1986 onward.

A clutch rated beyond the transmission's torque figure

The gap between the gearbox's 700 lb-ft torque rating and the clutch's roughly 800-horsepower capacity reflects that the two parts are rated by different measures, torque for the transmission and horsepower for the clutch's holding capacity, rather than one overriding the other. A 0.63:1 double overdrive sixth gear keeps highway RPM down despite that strength, while the 26-spline input and 31-spline output shafts carry the load.

What ships in this kit, and a seal-era caution

This kit includes the bellhousing and a shifter as standard, along with a 10-inch performance clutch disc, a heavy-duty pressure plate, an SFI-approved billet steel flywheel, and a hydraulic throwout bearing. Because 1986 is when Chevrolet switched to a one-piece rear main seal on these small blocks, an engine built before that change needs a different kit, not this one.

What warranty applies? The kit carries its own 1-year warranty against material and assembly defects, though some individual components may carry separate manufacturer coverage.