64-67 GM A-BODY MDL Modified Tremec TKX 5-Speed/.81-OD


Due to the popularity of this item
We ask that you please call for availability. 208-453-9800

Gear ratio 2.87, 1.89, 1.28,1,  .81od

– GM A-body 1964-1967

MDL mods bring the shifter stub up in the OE position

Click here to see what’s different


Available on backorder


Introducing the 64-67 GM A-BODY MDL MODIFIED TREMEC TKX 5-SPEED/ .81-OD
This shifter is a close-ratio custom-made piece that is now an integral part of the transmission

This is an upgraded transmission, this isn’t just a bolt-on shifter.
They are all prepared at our facility by hand to ensure quality & precision.
Many hours of R&D were put forth to provide this to you our customer.

No upgraded TKX leaves here unless it’s right.

What do we do to the TKX:

MDL modifications bring the shifter stub up in OE position
We achieve this by carefully machining, updating, and integrating new pieces to 
this HOT NEW must-have transmission
Not available through TREMEC.

  – GM A-body 1964-1967   

  –  Gear Ratios 2.87, 1.89, 1.28, 1, .81od
  –  26 spline input, 31 spline output

** NOTE: C1 Corvette requires fabrication of cross-member.

MDL mods bring the shifter stub up in the OE position


Click on the link below to see the installation article by: Jim Smart

TKX Performance for C2/C3 Corvette


Reserve yours now… call us for details & availability  208-453-9800


TKX is the next generation in five speeds
With  ALL NEW End-Loading Design
Which provides such advantages as:

  • a slimmer case design for great tunnel clearance
  • increased case strength, and fewer case seams.

All this and 8000 RPM shifting & 600lbs/ft. torque capacity

Sintered carbon/bronze-Hybrid triple cone synchro’s with a non-leading tooth profile


Product Features


  • Sintered carbon/bronze-Hybrid triple cone synchro’s
    with a non-leading tooth profile.
  • Close gear ratio (2.87, 1.89, 1.28, 1.00, .82) high-performance applications
  • Utilizes GM TKO bolt pattern & 7.2″ length input shaft
    (with a short input shaft option you can bolt to:
    GM close pattern 3-4 speed bellhousings)
  • 26-spline input shaft & a 31-spline output shaft for added strength.
  • GM  .590 pilot tip and 1.375″ OD throwout bearing guild tube. 
  • Robust design with an internal 3-rail shift system & steel shift forks.
  • All gears & shafts are made from special grade steel (ASTM 4615) for the increased demands of today’s engines.
  • Single-piece countershaft provides an increased torque carrying capacity.
  • Tapered roller bearings on input, output & counter shafts improve performance
    ….(reducing noise factor) with a caged needle bearing on the main shaft. 
  • Equipped with an MDL high-performance short-throw billet aluminum shifter that isolates road noise, while providing clean crisp shifts. 
    …..(See more detail on the MDL shifter here)
  • A new smaller mid-position shifter mounting base reduced the footprint
  • Built-in reverse light switch on the left side
  • Cruise control safety switch location on the right side of the TKX.
  • The rear main-shaft support bushing moved from the tail closer to the gearbox provides better support.
  • All mating surfaces are sealed with gaskets


If you are making over 400 hp and need an update from your four-speed this is the transmission for you.

We offer complete TKX five-speed packages
They are totally customizable.
Contact us today for a detailed quote.




Experience the MDL difference:

When you purchase a complete MDL Conversion Package you get

  • We extend the manufacturer’s warranty by an extra year… with a 1-year grace period.
  • We have the best in the industry customer service.
  • lifetime technical support.


TKX offers even more:

  • Three shifter locations are standard.
    (For the Mid position, an additional kit is required)

  • Ford Mechanical 7-tooth speedometer cable drive gear
  • The reluctor wheel is 17-tooth.
  • OSS two-wire Analog speedometer sensor built-in.  
  • Reduce engine rpm to a level that makes it fun to drive besides enhancing fuel efficiency.


Lubricant Specifications

For all Tremec TKX 5-Speed models, the recommended oils are
Amzoil ATF or Synchromesh
Tremec High-Performance manual transmission Fluid (HP-MTF)
GM Synchromesh
Mobil 1 Synthetic ATF.

Fluid capacity is 2.7 quarts / 2.6 Liters.


Additional information

Weight 1936 oz
Dimensions 48 × 14 × 18 in







TKO / TKX Oil info




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