67-68 Mustang 5 & 6 Speed Conversions

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New TKX in a ’67 Coupe


TKX ‘Qwik Stick’ Shifter


TKX offers more room than TKO


















MDL Clutch Master mounted to firewall















































67-68 Mustang 5 & 6 Speed Conversions 

If you’re updating from Auto to 5-speed
Or If you just want more driveability from your manual transmission Mustang.
We can help with that.


  • Increase in fuel economy with overdrive.
  • Lower RPM’s for more drive-ability and a much quieter in-car feeling. 
  • Reduce wear on your engine & drive-train parts
  • Reduce engine temperatures, promoting a longer-lasting engine.


Experience the MDL Difference:

  • We extend the manufacturer’s warranty by an extra year… and that’s from the date of install.
  • MDL offers the best in the industry customer service.
  • When you purchase a complete MDL Conversion Package you get, life-time technical support.

What’s in an MDL conversion package?

67-68 Mustang 5 & 6 Speed Conversions are TAILORED to your needs
With many or all of the following:

TREMEC 5 or 6-Speed Transmission with Shifter

All Fastening Hardware including

T5 Five-Speed Single Overdrive Conversion

Inline Six-cylinder conversions

By 1967, Ford settled on the 3.03 three-speed with the wide pattern “Toploader” pattern.
The three-speed was budget-minded and were great in their day… Fast forward today, these same transmissions are worn out are in the need of replacement, this is where our
67-68 Mustang 5 & 6 Speed Conversions come in.

One option is a Tremec T5 five-speed with an overdrive.
This allows the Mustang to travel comfortably at highway speed at mid 2,000 rpm range.  Installing a Tremec T5 into a classic Mustang is easy.
Using most of the three-speed parts like the bell-housing, flywheel, and clutch linkage, all that is needed is a new conversion clutch, adapter plate, T5, cross-member, and a few other supporting parts. No tunnel modifications are needed and the shifter location is retained.

If there are 2 starter bolts this means the flywheel is a 136 tooth with a 9″ clutch.
MDL has the T5 adapter plate to make this conversion easy.

OK, your classic Mustang is equipped with an automatic. MDL has a complete conversion package to make this easy.

Our T5 conversion kit includes hard-to-find items like an inline six-cylinder flywheel, conversion clutch, reproduction easy to easy-to-install clutch pedal, the correct slip yoke for ready-to-bolt in the driveshaft, and everything in between.

V8 Conversions

Manual to Five-Speed

Six bolt 289/302/5.0L equipped

The Mid-year 1966 Mustang was equipped with six-bolt blocks that carried through 302 and 5.0L HO of the ’90s. 

Along with this change came the wide pattern “Toploader” four-speed. 
Modern DriveLine’s adapter MD-401-2102 bolts to the bell housing to allow the Fox-body T5 bolt right up using all the stock clutch linkage.
Another option for installing a T-5 behind a six-bolt block is the fox body T5 bell housing.
With this bellhousing, you don’t need an adapter plated and you can use a 157-tooth flywheel from the 3 or 4-speed.

With a T5 bellhousing you have three choices in clutch Release. Stock mechanical linkage, cable, or hydraulic.


 Mechanical linkage:

T5 bell housing is designed for cable release and is deeper. 

To install a mechanical fork, a fulcrum kit is required to mount the fork.
The kit has a spacer to keep the fork in the same location.
MDL can pre-drill the mounting holes for you with our fixture to ensure the mounting hole location is correct.


Cable clutch release:

Since T5 bell housing is designed for a cable release, a matching fork is required. It is important to know the 3 or 4-speed mechanical release clutch can no longer be used as it will be too tall.
MDL offers cable release clutches for 10″ long pattern and 10.4″ Metric bolt patterns.
The pressure plate lever height is lower and the release is faster.  Using the stock clutch pedal, MDL engineered a cable kit that bolts to the 65-66 Mustang pedal and comes complete with a firewall plate, custom double adjustable cable. The cable is routed around the exhaust system and down along the oil pan to the clutch fork.

Check out the clutch cable kit here

   Hydraulic release:

MDL’s Sema award-winning Team has developed a complete line of hydraulic clutch release systems we call our LF (Light Foot) Series.
The master cylinder mounts on the firewall using the mechanical linkage that connects to the stock clutch pedal.  Custom linkage provides proper leverage, and control while providing design flexibility.
Using the T5 and cable fork, our external slave cylinder mounts the back of the bellhousing pushing the fork forward.

Our engineered hydraulic system provides the most exhaust clearance while giving you the softest pedal effect.


From our How to Series: How to get a soft pedal with our LF series hydraulics

Helpful Videos:

Check out a Video for this install featured on  TWO GUYS GARAGE

67-68 MDL conversion package Install by CJ PONY PARTS


If you are undecided as to which clutch release system is right for you, we can help you through the process of what is right for you.

TKX Five Speed Single Overdrive Conversion up to 750hp

For higher torque applications or you’re a ‘spirited driver,’ the TKX series five-speed is the latest offering from Tremec
check out these stats.

Rated for 600lb/ft of torque, will support shifting up to 8000rpm thanks to triple cone hybrid sintered synchronizers that the Tremec TKX has to make your driving experience the best.

The new end-loading design makes for a stronger case with a new sleeker profile, eliminating top covers, that would have restricted room in the tunnel.


To Shop TKX click here

To learn more about the new TKX click this link.

Below you can see the differences between the TKO & TKX cases



The TKX offers a little more adjustment approx. 5/8″ at the tail shaft vertically for the driveline angle.
Perfect for Pro-Streeters who love to tuck the rear suspension up into their ride.

There is no need to cut the tunnel or move anything TKX fits nicely in the ’67-68 Mustang
A great addition to the installation is the MDL Crossmember item# MD-6773M-CMTKO and a new mount,
This will maintain the transmission angle as well as providing superior clearance for exhaust and a locating arm for your emergency brake cable.

TKX Five Speed Single Overdrive Conversion

The big brother Five speed.  Perfect for those of you running a high-powered small block or big block.
Tremec developed the TKX to be as much of a direct bolt-in replacement for the wide pattern Ford Toploader and input shaft features.
For early Mustang is best to keep the standard length TKX input shaft to keep the shifter back in the tunnel shift hole.
We do this by using a 3 or 4-speed bell housing to TKX spacer or switch to a TKX bell housings.

Modern Driveline Exclusive Solutions:

MDL offers a wide range of bell housings for SBF, FE, 429 series blocks.  Tremec TKX’s are offered in two-gear ratio gear sets.
The TKX comes with a wide-ratio 3.27:1 first gear with a .72:1 OD.
OR a close ratio with a 2.87:1 first gear with a .68:1 or .82:1 OD.

For small blocks, the TKX will fit in the transmission tunnels with the use of an MDL TKX crossmember and standard top covers.
Since big blocks fit differently, it is best to use our low-profile top covers and low-profile crossmember for additional clearance.



T56 Magnum Six-Speed Double Overdrive Conversion

Magnum Six-speed is the top of the heap when it comes to manual overdrive transmission with its brute strength of 700ft/lbs. TQ. and two overdrive ratios.
In order to fit a Magnum in a 67-68 Mustang, the tunnel has to be enlarged, once this is accomplished, the sky is the limit.
The Tremec T56 Magnum can be bolted behind just about any power plant you can dream up.
From a Small block to a Big block or Module Coyote, the Magnum Six-speed with handle high loads down the strip or just pro-touring the open road.
Our conversion package is very complete with many choices to custom tailor the six-speed to meet your needs.
With the Six-speed we highly recommend our LF series hydraulic clutch release for a light soft-pedal that provides lots of header clearance.
In just 15-20 Minutes we can build you a detailed custom quote for you to review.

Automatic or full conversion packages

Modern Driveline has perfected the automatic to five-speed conversion.
When you contact us we will ask you a shortlist of questions to better understand your needs and wants.
Using our 67-68 Mustang 5 & 6 Speed Conversions, we can offer you everything you need to remove an automatic or completely replace the stock 3 or 4-speed gearbox.
If your project demands everything from scratch, we’ve got you covered.


When removing an automatic, nothing remains.
Our automatic kits provide everything from the block to the second u-joint.
It is important to know which balance crank is installed in your motor.  289/302 up to 1980 from the factory were 28 oz imbalanced.
All 5.0L from 81-95 are 50 oz imbalanced unless the crank has been changed.  Today there are many that are building zero-balanced SBF like Ford Racing. 

Let us know what you are planning to run.  We will suggest the right clutch to run based on your horsepower and driving style.  In most cases, we can have a detailed quote prepared for you in under 15-20 minutes.



Click or call for a customized quote for your requirements.





Installation Article of a T5 into a 1967 Mustang


An MDL Customer’s account of a TKO to TKX Swap

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