TREMEC TKX 5-Speed Conversion Package | 1955-1957 Tri-Five Chevy | LS Engine

TREMEC TKX 5-Speed Conversion Package | 1955-1957 Tri-Five Chevy | LS Engine

TREMEC TKX 5-Speed Conversion Package | 1955-1957 Tri-Five Chevy | LS Engine

Description

Key Features

  • 600 lb-ft torque capacity with 8,000 RPM capability and safe shifts at 7,500 RPM
  • Multiple gear ratio configurations - wide ratio (3.27:1 first, 0.72 overdrive) and close ratio (2.87:1 first, 0.68 or 0.81 overdrive) options
  • 26-spline input shaft with 31-spline output shaft for maximum driveline strength
  • Compact end-loaded case design fits Tri-Five tunnels with minimal modification
  • Completely customizable package - select transmission, bellhousing, clutch, flywheel, hydraulics, and crossmember to match your build
  • Three shifter positions available - forward position clears original bench seats for period-correct interior appearance
  • Ribbed three-piece aluminum housing provides structural stiffness with reduced NVH
  • All gears and shafts forged from special-grade ASTM 4615 steel for increased torque capacity and gear life

Description

Dropping an LS into your '55-'57 Tri-Five delivers modern power, but pairing it with a worn-out automatic or tired four-speed wastes that potential. This fully customizable TREMEC TKX package solves the drivetrain equation for LS-swapped One-Fifty, Two-Ten, Bel Air, and Nomad builds - delivering 600 lb-ft of torque capacity, crisp 7,500 RPM shifts, and a single overdrive gear that drops highway RPM while adding smiles per mile. The TKX's compact end-loaded case was engineered specifically for tight classic tunnels, fitting where bulkier transmissions won't without extensive floor surgery.

Inside, the TKX represents a ground-up design built exclusively for the aftermarket. Multi-cone synchronizers with hybrid sintered bronze and carbon rings deliver smooth, precise engagement even at high RPM - no more notchy, balky shifts from truck-derived gearboxes. Wide gear widths and caged needle bearings in all positions maximize durability under hard use, while the three-piece ribbed aluminum housing provides the structural stiffness needed to keep everything aligned under load. Gaskets at all flanges eliminate the sealer mess and leak potential of older designs.

What makes this package exceptional is complete customization for your specific build. Choose from multiple TKX gear ratio configurations to match your rear axle ratio and driving style. Select LS-specific bellhousings with provisions for hydraulic or mechanical clutch release. Pick from street-friendly to race-ready clutch assemblies matched to your power level. The guided package builder walks you through each selection, or MDL's concierge service can help spec the perfect combination for your project and budget.

The forward shifter position maintains OEM bench seat clearance for that authentic '50s interior while delivering modern shifting performance. Compatible with 1955-1957 Chevrolet passenger cars (excluding convertibles for some components) when equipped with Gen III/IV LS-series engines. Professional installation recommended due to hydraulic system integration and driveline modifications.

What's Included

This is a customizable package system - select components based on your specific build requirements:

  • Transmission Options: TREMEC TKX 5-speed with choice of wide-ratio (3.27, 1.98, 1.34, 1.00, 0.72) or close-ratio (2.87, 1.89, 1.28, 1.00, 0.68/0.81) gear sets - 26-spline input, 31-spline output
  • Bellhousing Options: LS-specific aluminum bellhousings with hydraulic or mechanical release provisions
  • Hardware Kits: Transmission-to-bellhousing mounting hardware in aluminum or steel configurations
  • Flywheel Options: LS-specific SFI-rated flywheels for various crankshaft configurations
  • Flywheel Hardware: Grade 8 or ARP flywheel bolts
  • Clutch Sets: Street to race clutch assemblies sized for your torque requirements
  • Pilot Bushing: Twin-disc pilot bushing option available
  • Pressure Plate Hardware: Standard or ARP pressure plate bolts
  • Hydraulic Systems: Master cylinder kit, braided stainless steel line, and hydraulic release bearing
  • Shifter Components: Handle options, shift boots, and knobs including MDL-branded options - thread adapters available
  • Support Components: Tri-Five specific crossmember, transmission mount, speedometer adapters/gears/sensors, and reverse light harness
  • Fluids: TREMEC HP-MTF transmission fluid
  • Driveline: 31-spline slip yokes in 1310, 1330, or 1350 U-joint configurations
  • Technical Support: MDL installation guidance and ongoing tech support
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