Categories: , , , SKU: 71-73 MUSTANG 5 & 6 SPEED CONVERSIONS






















5 & 6-speed conversions
For Small Block, Big Block or Mod Motor swapped Fairlanes
Our line of products offers simple ways to upgrade your 3 or 4-speed
to a Tremec five-speed or a complete automatic to five or six-speed overdrive.
  We have you covered.

For those owners who want to upgrade from Auto to 5-speed
If you just want more driveability from your manual transmission Mustang or want to make it more modern with a 5 or 6-speed, we can help with that too.

Experience the MDL Difference,

  • We extend Tremec’s factory warranty by an extra year.
    And add a 1-year grace period.
  • We offer the best in the industry customer service.
  • When you purchase a complete MDL Conversion Package you get, lifetime technical support.

TECH GUIDE: Simple Five-Speed Swap for Your 71-73 Mustang

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 not great in their day.
Fast forward today, these same transmissions are worn out are in the need of replacement.
The answer is a Tremec T5 five-speed with an overdrive.  This allows the Mustang to travel comfortably at highway speed at the mid 2,000 rpm range.
Installing a T5 into a classic Mustang behind is easy.  Using most of the three-speed like bell-housing, 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″.  MDL has the T-5 adapter plate that 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 a new inline six-cylinder flywheel, conversion clutch, reproduction easy to install clutch pedal to 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

Mid-year 1966 Mustangs were equipped with six-bolt blocks that carried through 302 and 5.0L HO of the ’90s.  With this change comes the wide pattern “Toploader” four-speed.  Modern Driveline’s MD-401-2102 bolt to the bellhousing to allow the Fox-body T-5 bolt right up using all the stock clutch linkage.   Another option to installing a T-5 behind a six-bolt block is the fox body T-5 bellhousing.  With this bellhousing you don’t need an adapter plated and you can use a 157 tooth flywheel from the 3,4 speed.

Cable clutch release – Since T-5 bell-housing is designed for a cable release, a matching fork is required. It is important to know the 3,4-speed mechanical release clutch can no longer be used as it will be too tall.
MDL offers cable release clutches for the 10″ long pattern as well as the 10.4″ Metric bolt patterns.  The pressure plate lever height is lower and the release is faster.
To use the stock clutch pedal, MDL engineered a cable kit to the bolts to the 65-66 Mustang pedal and come complete with firewall plate, custom double adjustable cable the is routed round exhaust system.

Click Here:  to check it out


From our Here’s How to Section: ; Building Generations; installs a T5 into a ’71 Mustang

Installing a 5-Speed into a 1971-73 Mustang/Cougar

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 T56 Magnums have 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.


From the still photos below, you can see the clearance you can expect with a stock cross-member & mount.



Click here to read more about the TKX



Above 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.
This can be done by removing the factory spot welds and relocate the support back.
A great addition to the install 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 brack cable.

T-56 Magnum Six-Speed Double Overdrive Conversion

Tremec’s Magnum Six-speed is the top of the heap when it comes to manual overdrive transmission with its brute strength of 700ft/lbs and two overdrive ratios.
In order to fit a Magnum in a 71-73 Mustang the tunnel has to be enlarged, once the is accomplished, the sky is the limit.  The T-56 Magnum can be bolted behind just about any power plant you can dream up.
From a SBF to a Big block or Module Coyote, the Magnum Six-speed with handle high load down the strip or just pro-touring the open road.
Our conversion package is very complete with many choices to customer 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 auto 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 complete line of products, we can offer you everything you need to remove an automatic or completely replace the stock 3,4-speed gearbox.
If your project demands everything from scratch, we got you covered.

When removing an automatic, nothing remains.  Our auto kit provides 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 280oz imbalanced.
All 5.0L from 81-95 are 50oz imbalanced unless the crank has been changed.
Today there are many that are building zero-balanced SBFs 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.  Get Quoted in under 15-20 minutes.

VIDEO: Installing a pedal in your 71-73 Cougar

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

Converting from Auto to 5-speed or If you just want more driveability from your manual transmission mustang
Or want to make it more modern with a 5 or 6 speed we can help with that too.

1971-73 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

71-73 Mustang 5 & 6 Speed Conversions by MDL are as complete as possible.
You get ALL the components you need where competitors’ packages provide only the basics.
When comparing costs be sure you are comparing apples to apples on the contents, quality & after the order service.

MDL is a stocking distributor which means…most components are IN STOCK & ready to ship


Click or call for a customized quote for your requirements.

Components are IN STOCK

Check out David’s Mach 1 upgrade here