Watch Robert Hall of American Powertrain and Chad Reynolds of go over the new TKX

The New TREMEC TKX is the new 5-speed in town. TREMEC has normally sourced their aftermarket transmissions from the OE side, such as the Magnum T-56 and the T-5. This brand new design is made from the ground up as a strictly aftermarket transmission. Designed to fit classic muscle cars and customs, the TKX has a tighter, more streamlined case.

TKX 5-Speed Manual Transmission Features and Benefits

  • The TKX has 600 lb.-ft. of torque capacity and is capable of engines speeds of 8,000 RPMs with shifts at 7,500 RPMs. It is available in multiple gear ratio configurations (See chart below).
  • Designed for multiple applications with three shifter locations. Compact, end-loaded design provides clearance in most transmission tunnels without floor modifications.
  • Increased case strength with three-piece aluminum housing provides outstanding structural stiffness (includes main case, intermediate plate and rear extension). Gaskets at all flanges simplifies installation and eliminates fluid leaks.
  • Superior shift-ability through use of multi-cone synchronizers and hybrid synchronizer rings made of sintered bronze and carbon
  • Noise, vibration and harshness (NVH) minimized with gear layout to best control stress levels. All gears supported by caged needle bearings to reduce end play on the gears.
  • All gears and shafts made from special grade steel (ASTM 4615) providing increased torque carrying capacity.
  • Equipped with a high-performance short-throw billet aluminum shifter that isolates road noise, while providing clean, crisp shifts.
  • Robust design with internal three-rail shift system and steel shift forks.
  • Wide gear width increases gear life and torque capacity.
  • 26-spline input shaft with a 31-spline output shaft for added strength.
  • Built-in reverse light switch and cruise control safety switch.
  • Separate GM and Ford case patterns and input configurations. Integrated GM and Ford transmission mount patterns.

American Powertrain can also provide a mid-shift conversion, as well as a White Lightning shifter. The White Lightning Shifter features over 60 additional shifter locations to help get the new TKX set up for your muscle car, truck or custom project. American Powertrain will also have a direct fit version for Classic Corvettes and Mopars, which feature a 12-month/12,000-mile warranty backed up even further with American Powertrain’s two year warranty. Check out the images below and the new TKX Gear Ratio Chart….

TKX Gear Ratio Chart

Check out the rendering from Tremec showing the size differences in the TKX, TKO and T-5. TKX is in green.

We are taking orders for the TKX now. They will be shipping from TREMEC around Nov. 30th. Call us at 931-646-4836 to get your order in line. Click here for more.

The TKX with more streamline case
TKX top view.
TKX electronic speedometer output and VSS output

Corvette C1 C2 and C3 version coming soon!

TKX with the American Powertrain Corvette C2 Pro-Fit conversion
TKX with the American Powertrain Corvette C2 Pro-Fit conversion
TKX with American Powertrain Mid-shift conversion

148 thoughts on “The New TREMEC TKX

        1. Honestly we do not really know yet as we have not had time to fit the TKX to all the applications since TREMEC just came out with it. TKO you have to cut the floor for sure. TKX is smaller but A-body mopar has a really small tunnel. So to be safe I can’t tell you yet you wont have to modify the floor until we get all our engineering done.

    1. We have all that. Just call us for a quote on an A-body conversion kit. TKO kits have been around for years. The TKX is the same except it fits the floor better. You need to have the right offset shifter for the transmission which we make just for the console cars.

  1. Im doing a different engine swap and was looking to see if you offer kits for different motors? Its a 2.8l vr6 out of a vw.

  2. That sounds cool and all. But I would like to have one specifically made for the 4.3L V6 Chevy engine. Because it would be nice for us gearheads who like muscle but don’t like the fuel economy of the V8 engines.

    1. It does sound cool…..You know the 4.3 has a small block chevy bolt pattern right? the TKX bolts up to any SBC bell housing…We have all the stuff you need to make it work.

  3. Will this be a direct fit with no modifications for a 69 camaro .Do i need a different crossmember .What else do i need thanks

    1. Yep…You need our TKX Pro-Fit kit for 1st Gen Camaros. Give us a call at 931-646-4836. We do our quotes over the phone per application since there are many options.

  4. I’m interested the TKX in close ratio with .81 for my 65 Fastback Mustang in 10 spline input is that possible? Also how much work will need to be done if any to the Transmission Tunnel to fit?

  5. Wondering if this will fit in an early model 1965/66 mustang without having to modify the floor pans? Thanks!

  6. Sounds real good, but I got one for you. Do you have a version that will fit in a 1973 pinto four cylinder 2.0 liter?

  7. Same input spline as a Muncie? I can use my old clutch disc on my small block Chevy V8? How about the transmission yoke same number of teeth? How about the length of the transmission is it the same?

    1. No its 26-spline. Its longer and you have to have a new driveshaft made. 31 spline yoke. It bolts up like a muncie. We have been doing the kits for years with the TKO for munice cars. We make the drive shaft and supply the correct crossmember and all that. Just give us a call.

  8. I have a 1963 Ford Galaxie with a 429 installed. I want to switch from AT to manual and have been looking at the TKO, so this is good news.
    Do you offer a bellhousing, flywheel, release bearing, the new TKX with a shifter location close to the stock one.?
    I have a full machine and fab shop on site, so a crossmember and motor mount position are flexible. I just need the shifter to fall somewhat close to the factory location. Will be using a set of stock car race pedals and master cylinders.

  9. Looking for a tkx kit for a 1966 chevy II. The car currently has a 283 v8 with a muncie 4spd. The car has a bench seat and 3:08 rear gears. I am considering changing the rear gears to 3:73 with the tkx 5spd.

  10. Do you already have the mid-shifter kits worked out? Also, do these have the improved synchro and shifter rail systems more like a magnum than a TKO? There is definitely a difference in how a Magnum feels versus a TKO.

  11. I have a 1965 Chevy impala 396/four-speed, what transmission will fit without modifying the floor and will fit the stock console.

  12. i have a 1976 pontiac trans am 455 and a borgwarner 4speed . do you have a tkx kit for my car? the car has orginal consol and i dont like to cut in the floor is it possible with the new tkx? when is this kit ready for shipment and what is the part/order number for this kit?

  13. I have a 1993 Ford F150 Lightning, automatic 351windsor, 410 rear end. Would like to convert to manual and looking to free up final ratio for more cruising ability. Thoughts?

  14. Can you guys explain how you fit a T 56 in a 1965 Mustang without tunnel mods and keeping the correct driveline angle thanks?

  15. Hello – I have a 77 Olds 442 that I converted to a 4 speed. I have a 73 442
    4 speed console in her, will the TKX shifter be in the same place or will I need to cut the floor?

    Thanks Matt

  16. I have a 1967 C10 steptside short bed and the engine sits very close to the firewall. The engine is a 350 with 3.42 rear gear and a B/W super T10 4speed bench seat.Question: will your TKX fit without cutting the tunnel and would the shifter have to be moved to mid-position, and does it cost more to move the shifter?

  17. I just ordered the American Powertrain Tremec
    TKX transmission from Summit Racing! It says ship date is Jan. 18th, 2021. But I see you guys say you will start shipping on Nov. 30th, 2020. Should I expect my unit to show up in December 2020?

  18. I have a 1968 Camaro with an LS376 engine and stage 2 cam. I am looking to buy an engine and saw that the TKX might look a bit fit yet especially since it resembles in the most part the TKO 600/500 transmission, has the same torque capacity (600ft-lb), and has an 8,000 rpm max.. Would there be a kit available for this configuration? And if so what would be the pricing for a close-ratio kit that would have everything needed to just drop it in. Thank you!


    1. TKX and TKO are the same for any of our old kits. The TKX just replaces the TKO with a better case and better shifting. The best thing to do is fill out our RFQ link on the site or call us at 931-646-4836. We like to quote the kits since they have tons of options.

  19. Will this work in a Chevy 67 c10 , want to use original truck bell housing and clutch fork , rear cross member is a th350 that I have , I can have drive shaft done locally, I will need A yoke? Rear gears are 4:11, what OD Would be better.

    1. Yes it works we have complete C10 kits. You will need to cut the floor or get one of our C10 tunnel humps with your kit. It does come with a yoke. But keep in mind our Pro-Fit kits come with a new driveshaft. Just call us at 931-646-4836 for a quote.

  20. Looking for a belhousing to mate the newer duratec- mazda-ford 2.5 with a ford spec of the tkx.. The mustang ecoboost 6speed bolts right up too the 2.5… But I don’t want to go thru the hassle of that swap as the tkx is much stronger.

  21. I am building a 445 FE Ford putting together a street/strip 68 F100 short bed. Can we use this TKX. I have the TKO600 in a 91 fox and love it. My concern is shifter placement.

  22. Will the TKX work without any tunnel cutting or oddball shift lever orientations in a 2008 Mustang GT? Is it compatible with the S197’s input shaft-mounted throwout bearing and are there any known spacer requirements? I’m looking at the TKX as a possible alternative to the Magnum XL, for use at HPDE track days where at least 3rd, 4th, and 5th are closely spaced, with 5th gear being around 0.8. It looks like gearing in the TKX would be slightly better around town than a 2.66-low Magnum, and not quite as good for long highway stretches.

    1. It will fit but you are taking long way around to get gear ratios you want. We can change gear ratios on a Magnum XL which will fit 1000 times better in that car. Give us a call at 931-646-4836

    1. They took out the torque arm provision . I watched a video where they said they where going to work out some kit that the torque arm would probably be attached to the crossmember i think . Im also waiting to hear more about this . I cant wait for this trans . I have a 3rd gen Fbody as well

  23. I bought a frame from tci for a 36 ford it was built for a gm 4 speed. Can I convert it to your new 5 speed with out modify the frame?

  24. Thanks, Matt. Either way, it’s a long-lead kind of thing and I’m mostly looking to see if there are any hard deal-breakers with respect to the TKX. To date, the Magnum XL has been the leading choice, but then the TRX showed up as an alternative at least worth looking into.

  25. I have today a 65 Mustang with a 5.0 and a t-5 trans
    what do I need to put a TKX in the car?
    Rolf Johnsson Sweden.

  26. I have a ’61 Falcon with a 408w and a t-5. What am I looking at to swap this in? I’m already drooling at the thought of not having to worry about grenading my tranny if I unexpectedly find to much traction.

    1. We have an E-body kit in R&D right now. It will be done mid Jan. You will not have to cut the floor. But a stock TKX out of the box will not work. You will need our kit.

  27. Which TKX is compatible with my 1966 Mercury Comet Cyclone 390 GT? What bellhousing do I use? Will the stock crossmember work with TKX? What effect will TKX have on diveline pitch to rear axle housing? Will TKX shifter fit stock cut out in center tunnel?

  28. What is the size (dia) of the bearing retainer on the front of the transmission, want to mate it to old truck bell housing in a 67 c10 1/2 ton in place of truck 4sp,

    1. We strongly suggest getting a new bell. Those old C10 bells with the motor mounts are sketchy at best for proper bell alignment on a modern transmission. We have gone down this road a lot with customers on those. Any muncie style new bell will work. We also sell them.

  29. I have a 39 Chevy coupe with an LS3 7004R combo now with no floor pan mods.
    Do you think the TKX will fit in the same basic location? I am not opposed to some mods but would rather not have to if possible. Also do you offer an install kit like some others? (bell, clutch, flywheel, ECT,,,)

  30. Hello,
    I would like to know will this new TKX box bolt straight up to a Cleveland engine standard bell housing pattern or is there sum mods I would have to do, I have a 1970 falcon.


  31. I see tremec is close until January 4th by there web site. Do you have a realistic time when they
    Will begin shipping the tkx? I already have a order with americanpowertrain.

    1. I wish we did. We have over 100s of units on order so we are waiting on a shipping notification from them. Currently we think its going to be mid Jan or end of next week before the first batch gets here. A lot depends on when you placed your order.

  32. I have a 55 Ford custom line I was wondering if the new TKOX will go in without hump modifications on this it has a 410 FE motor in it was a four-speed now

  33. I currently have a t-5 swapped in to my 1965 mustang that is pretty overpowered by my new motor. What modifications would be needed to swap in the TKX?

  34. Hi will TKX fit for 63 Impala orginal 4 speed car with floor console, do you have shift kit for it ? Going for Ls swap .

  35. Does this use the same bolt pattern the TKO uses for a GM? So If I had a TKO600 already and wanted to switch to this I wouldn’t have to change the bellhousing?

  36. 1970 Chevy nova ss396 factory four speed , no console car . I like the TKX as an option , wondering about the floor and any cutting or trimming , the car is an original 396-375 , I don’t want to cut up the floor . Also can a factory clutch set up work ? I have a m-22 now with 1350 u joints , any info would be appreciated , thanks

    1. It will fit with no cutting. you can reuse all the factory linkage, crossmember and bell housing. You will need a 26 spline clutch and a new driveshaft since its a longer trans and has a much larger yoke 31-spline. We have all that. We do A-bodies in our sleep.

      1. Thanks Matt , so if I get the trans mission n shifter , do I need a different crossmember ? And how about a ruffcost on the conversion ? Thanks again

  37. Has there been any verification on fitment of the tkx in a Mopar a body with or without floor modifications. Also, I placed my order in late November. Any updates on when orders will be fulfilled?

    1. We still have not verified fitment on Mopar A-body. We are finishing up B and E body right now. We have a lot going on in R&D just trying to get to all these designs. A-bodies are so tight on the floor it’s going to be close. Tremec is telling us now Ford TKXs will be shipping in March. They are building GM units first those are rolling out in Feb. Sorry for the delay. Since you ordered in Nov you will be one of the first in March to get a Ford unit.

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