SBF 600HP TKX 5SP Wide Transmission and Clutch Conversion Kit

This is a bolt-in manual-swap package built around the genuine TREMEC TKX wide-ratio 5-speed, sized for Small Block Ford applications that need to handle 600 lb-ft of torque and engines making up to 750 horsepower. It pairs the transmission with a steel Quick Time bellhousing, a dual-disc clutch, and a hydraulic release bearing so the harder parts of a manual conversion arrive already matched to each other.

Where it bolts in

The kit targets 289, 302, 347 stroker, and 351W small-block Fords, with flywheel balance supplied in a 0, 28, or 50 ounce configuration depending on which of those you run. Gearing is wide, starting at 3.27:1 in first and dropping to a 0.72:1 overdrive in fifth, with shifts smooth to 7,500 rpm and an 8,000 rpm ceiling. The case is aluminum and the whole assembly comes in at roughly 99 lbs dry. The input side carries 26 splines on a 1.0625-inch shaft, while the output end runs 31 splines on a 1.375-inch shaft.

Before you order

Plan on a matching transmission crossmember, a 31-spline slip yoke sized to your driveshaft, a hydraulic clutch master cylinder, and a transmission mount, since those aren't part of the box. The 10.5-inch dual-disc clutch and billet flywheel keep pedal effort close to stock. Fill with roughly 2.7 quarts of TREMEC-specified high-performance manual transmission fluid. A one-year limited warranty backs the kit against defects in materials and workmanship.

Will it fit a stock Falcon or Fairlane tunnel? The case is compact enough to need only minor tunnel work on most of the classic Ford platforms it targets. Do I need a new driveshaft? Likely a length change to match the 31-spline slip yoke, since the output end differs from a stock automatic.