How to pick the right T-56 Transmission for your build–and your budget

Background and Evolution

To understand the T-56’s popularity, let’s start with its birth. It was originally designed and built by BorgWarner for the 1992 Dodge Viper. A year later GM started using it in the Camaro Z28 and Pontiac Trans-Am. Initial reports? It was a tough, modern gearbox.

Tremec bought BorgWarner’s manual transmission business in December 1996, and since 1998 the T-56 has been built by Tremec. Despite their new mommy, internally the transmissions are identical.

The T-56 has been primarily associated with GM products. In addition to GM’s F-bodies, this transmission has also made appearances in the Chevy Corvette, Pontiac GTO, Cadillac CTS-V and Chevy SSR, but that’s just the tip of the iceberg. By American Powertrain’s count, there are 39 flavors of T-56 in the world, not counting its later offshoots, the TR-6060 and T-56 Magnum.

Most of those variants are indeed found in GM cars, but not always. Aston Martin and, yes, Ford, have also used the box. In a world that seems to be more and more polarized, at least Ford and Chevy fans can agree on the T-56.

Why is this transmission, out of all the gearboxes ever made, so popular? There are a few reasons: For one, the transmission was built in fairly large numbers. It’s also reasonably light, features two overdrive gears, can handle a lot of torque, and easily fits today’s most commonly swapped engine, Chevy’s LS small-block V8.

All of this adds up to another reason to love the T-56: lots of aftermarket support. No matter what you want to do with, in, on, or around a T-56, there’s somebody offering a bolt-on solution.

What about the TR-6060? It was designed as a T-56 successor, with the goals being smoother gear changes and the ability to handle even more torque. As a result the TR-6060 features bigger gears and bearings, better shifting hardware, and a new synchronizer arrangement. By 2008 it had superseded the T-56 on showroom floors, and it can be found in applications like the Dodge Viper, Dodge Challenger, and every current GM muscle car except the Corvette. Unfortunately, the TR-6060 carries a relatively high cost and lacks availability on the used market.

The T-56 evolutionary tree isn’t limited to the TR-6060, though. Another branch leads to the Magnum. Here’s the CliffsNotes summary: all the benefits of the TR-6060 but designed for aftermarket customers, meaning it fits wherever a T-56 will. Two versions are available: GM and Ford. The GM box is a bolt-in replacement for the 1998–2002 F-body, while the other is designed for the 2003-’04 Ford Mustang. For greater flexibility, both versions of the Magnum feature multiple shifter locations and two different speedometer inputs.

Tremec also offers the Magnum XL. It’s longer than the standard Magnum and was originally intended for the S197-chassis Ford Mustang.

How to Choose a T-56

So, you’re sold on a T-56 for your next swap. How do you pick one? Whether you’re junkyard scrounging or ordering online, our ID chart should help you pick a transmission that will match your engine and provide the proper gear ratios. To ID the particular T-56 transmission at hand, simply look at the tag bolted to the left side of the box.

But first, let’s walk through a few T-56 swap scenarios. Since most T-56s are fitted behind some variation of GM’s LS V8, we’ll assume that our hypothetical build is going to use one as well.

OPTION 1: Buy an LT1 T-56 and then convert it for use with your LS.

This method used to be all the rage, and the reason was simple: money. The 1993-’97 Camaro Z28 and Trans-Am are powered by the older LT1 V8 rather than the later, more desirable LS1.

“The biggest issue with the LT-1 is the pull-style clutch setup,” says Matt Graves of American Powertrain. “This gave them a very short input shaft and shallow bell housing that will not work with LS engines. In turn, this requires an LS1 front input shaft conversion so you can run a bearing retainer for an internal-style hydraulic clutch.”

Why isn’t this the best option? A few reasons. First and foremost, the parts are hard to find, and the newest LT1 T-56 is still 21 years old at this point. Tremec would rather sell new transmissions than parts for old ones, and people report waiting years for needed components.

The other issue is economic: These once-$500 transmissions have gone up in price–to nearly what you’d pay for a T-56 that will bolt right to your LS1. LT1 cars also feature a different clutch and flywheel assembly, meaning more money is needed to complete the swap. The economic incentive to mate an LT1-spec T-56 transmission to an LS has simply dried up.

OPTION 2: Buy an LS1 T-56.

This method is simple: Buy the transmission you need. You’ll mostly find 1998–2002 Camaro Z28 and Trans Am transmissions listed online, and if you can snag one for less than $2000, you’ve come out on top–and since these were all O.E. units, hope that the shifter location works for you. (T-56 units for Corvettes seem to bring in less money, but don’t forget that this is a rear-mounted transaxle, not a traditional gearbox.)

You-pull-it prices look attractive but can be a bigger gamble–that is, if you can find an LS1 T-56 at all. Our local LKQ currently lists all transmissions for $135.32 plus a $30 core charge, but they don’t have anything in stock that would bolt to our LS. There’s also a tendency for yards to pull desirable parts–like the T-56–so that they can be sold at market value.

Another consideration: Rebuilds can be expensive, and there’s no surefire way to gauge a transmission’s health once it’s sitting on a seller’s garage floor. The easiest diagnosis comes from taking the donor car for a test drive, but that’s not always possible. If you’re hunting for a transmission in the junkyard, look for a car that was totaled by a collision. That’s a good sign that the car was mobile until its untimely death.

What happens if you get unlucky and end up with a T-56 that needs a rebuild? Refer back to option one, where you could wait a year for parts.

OPTION 3: Buy a brand-new Magnum.

Yes, we may be the only car magazine that’s ever done a cover shoot in the junkyard, but that doesn’t mean used parts are always the answer. Because T-56s are in such high demand, buying new might actually be the better option.

Yes, it’s more expensive. American Powertrain lists a new Magnum for $3195 plus truck freight, but that delivers a brand-new, no-excuses gearbox that’s stronger and better-shifting than the T-56 and is available in wide- or close-ratio configurations. It’s also backed by a two-year warranty. (Budget $3695 for the Magnum XL.)

We entered this exercise assuming that used would be the best option for our own project–an LS1-swapped Nissan 350Z–but after weighing all the pros and cons, we decided not to gamble on a $2000 transmission that had covered 100,000 miles and nearly that many powershifts. We spent another grand to order a brand-new Magnum. We didn’t want to do this twice.