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68-79 Magnum 6-Speed Transmission Conversion (Manual to Manual)
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Everything needed for converting your original 3 or 4-speed 1968-1979 Corvette to a Tremec 6-speed manual transmission - perfect for those who desire improved performance, increased drivability while maintaining the stock look and feel.

Kit includes Tremec Magnum 6-speed OD transmission with custom machined PerfectFit side-mount shifter, transmission cross-member bracket, speedometer cable/adapter, 6-speed console emblem, reverse light adapter and dynamically balanced lightweight custom driveshaft with quick release slip yoke and u-joints. This transmission kit includes detailed instructions to complete the installation.

Tremec T56 Magnum kits have dominated the marketplace for well over a decade now. The PerfectFit Tremec conversions not only add value to classic cars but they provide unparalleled drivability without compromise to the original, factory looks. The Magnum 6-speed transmission is capable of handling 700lb-ft torque while handling shifts up to 7,800 rpms. Single rail, shift guide plate design means you'll never miss a shift! Fully synchronized - even in reverse. Interchangeable with both mechanical or hydraulic clutch actuators without tearing tear down the transmission. Great for everyday use - short, crisp shifts and a rewarding driving experience. 1-year warranty with a 2-year installation window. Tremec Magnum gear ratio 2.66, 1.78, 1.30, 1.00, 0.80, 0.63 or 2.97, 2.10, 1.46, 1.00, 0.74, 0.50. Specify final gear ration when ordering.

What to expect when converting your 1968-1982 Corvette to the Tremec Magnum 6-speed transmission:

  • 30-50% increase in fuel economy
  • Low RPM cruising for greatly reduced driver fatigue and an improved highway driving experience. Road trips are fun again!
  • Reduced engine wear leading to longer engine life
  • Cooler engine operating temperatures
  • Reduced NVH (noise - vibration - harshness)

Magnum 6-speed PerfectFit Kit Components Overview

  • T56 Magnum 6-speed Transmission - 700 lb/ft torque capacity - wide or close ratio
  • Perfect Factory Shifter Positioning
  • Multicone Synchronizer Blocker Rings are standard for low-effort, high RPM shifts
  • CAD Designed Transmission Crossmember - correct driveline angles, compatible with factory exhaust
  • Tunnel Patch - makes a tight seal to keep the weather out of your interior console
  • Driveshaft & Slip Yoke - Lightweight, steel, custom driveshaft for superior strength. Dynamically balanced for smooth operation and premium solid u-joints come standard
  • Speedometer Connection - Mechanical and electronic compatible
  • Calibrated Speedo Cable or Electronic Speedo Connector
  • Reverse Light Connector
  • Pilot Bearing - Super heavy duty needle roller type with lube seal for long life
  • Isolator Mount - Rubber for vibration isolation
  • 6 Speed Shift Pattern Plate - Maintains original appearance
  • Installation Hardware and Detailed Installation Instructions - including free lifetime tech support
  • 12 Month Product Warranty - Includes 24-month activation delay so you can finish your project.

Does not include shifter handle - can use your Corvette's existing bolt-on shifter handle or replace with Zip # TM-390 or TM-391 depending on application.

Tremec conversions are designed for manual to manual conversion. If you want to convert your factory automatic C3 Corvette to a 5 or 6-speed Tremec transmission - you can complete the Tremec conversion by ordering an "automatic to manual" conversion package from Zip Corvette. See Zip # TM-388 for the automatic to manual conversion. You'll be good to go from shifting to drive to slamming 1st, 2nd, 3rd, 4th, 5th AND 6th gear before you know it!

This item is proudly Made in the USA

Installation difficulty: 4

Our technicians have determined that the installation difficulty level of this item is a 4 on a scale of 1-5. Read more about our install ratings here.

Model Years

More Information
Generation C3
Model Year 1968, 1969, 1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979

Silver Sport

Silver Sport Transmissions modifies Tremec 5 and 6 speed transmissions to retrofit into your classic car, truck or street rod and includes any parts and accessories required to install them. Silver Sport’s PerfectFit™ Kits are made to last with only the highest grade parts included in their kits and all transmissions are quality tested for leaks, noise, and performance. Silver Sport Transmissions' experience runs deep. Their engineering, sales and technical staff provides a 75 year combined experience and the PerfectFit™ line of transmissions has been installed into more classics than any other on the market - so they’ll be perfect for your Corvette.

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