I've been looking at used T-56's for a while now, and I need to get a lot more educated about them.
I already read the T-56 swap postings, are there any other threads that I can search out?

I've heard people say that the '94-'96 German made units are better than the newer Mexican made units, and other lore. Is there a more desirable year range? And do the ratios change from different years? Are there any books with this kind of info about T-56's?

 

ignore the year / Mexico nonsense.

93 had two ratio sets. Either is fine at moderate power but 94-up with a different ratio set is stronger. But, the 94-up ratios are most drivable with a lot of rear gear, so that's a needed change and thus added cost for most swappers.

I don't know what books have T56 info other than the JagsThatRun TPI swap book.

What do you like about the 93-97 LT1 T56 that would fit your car well?
What do you not like about it?

 

The T-56 is a product of Tremec... which is an abbreviation of whatever "transmission Mexico" is in Mexican. That company bought out the Borg-Warner transmission line, as well as making their own products. So whatever you've heard about "German made" T-56s is a bunch of hogwash since no such thing exists.

There was however a German-made 6 spd in some cars for a few years; the ZF 6-spd. It was in Vettes and an extremely few F bodies (SLP Firehawks specifically) for a couple of years. Avoid it. Good transmission, but IMPOSSIBLE to find the bell housing to fit it into one of these cars since the sum total of sales of them was somewhere around 30; and the Vette one basically doesn't fit the car.

Ratios did change. As said, get the 94-up one and a high ratio rear gear.

Never seen or heard of a book on the subject. You'll find out more on this site than probably all the books ever written all put together.

 

Here is my take on the subject.

I prefer the aftermarket Tremec T-56.
It has several better features.

1st gear is 2.97, 5th gear is 25% OD & 6th is 40% OD. (same as T-5 in 5th)
Some will say it is not as strong, I am lauching my car w/400/430 HP TQ at 5000 RPM with no problems. (3700#)

It allows me to use 3.73 rear end and still be able to use 6th gear with a good size cam.

The other one....2.66 1st, 40% in 5th and 50% in 6th, that rquires 4.10's at least in the rear to use 6th gear.

The other nice part, it uses the square shifter so you don't have to cut a bigger hole in the floor to fit the larger shift plate.

Next, it can use the stock speedo cable or the electric VSS. (no box)

 

Here are the available ratio sets: 3.36 / 2.07 / 1.35 / 1.00 / 0.80 / 0.62 2.97 / 2.07 / 1.43 / 1.00 / 0.80 / 0.62 2.66 / 1.78 / 1.30 / 1.00 / 0.74 / 0.50 2.97 / 1.94 / 1.35 / 1.00 / 0.84 / 0.62 The first is the '93 LT1 with 2.73:1 axle. Second is '93 LT1 with 3.23:1 axle Then the '94.5-up LT1 / LS1 / Viper ratios, F-cars came with 3.42:1 axle Last is the retrofit box. Dyno Don is in error. And the L69 / LB9 T5 OD was 0.7280303:1, which is not an exact match for any of the T56 offerings. Nor was the 0.74:1 fifth offered in the retrofit T56, which was never less than $2400, but did include mechanical speedometer provisions. Takeout T56s are bringing about half that, which is still twice the cost of a used T5.

 

Uh oh. Someone copy pasta'd incorrect second gear ratio information.

And there's no such thing as an early 94 with the 93 ratios.

 

Wrong and wrong. The ratio info is direct from B-W circa 1995. second, B-W continued producing the '93 ratios through the end of their '93 production year, that has been documented. Unfortunately for you and me, there were no forums back in '93, or I'd've saved the proof. Were any installed in '94 F-cars? Nope. But the initial run of '94s were all automatics, there was a delay ramping up production of the Viper ratios. Remember, Viper used a bigger stronger output shaft.

 

M29 1993s and aftermarket run the same countershaft so 1-4 are the same.
That's just another old and commonly repeated error along the lines of the 2.74 first gear T5.

I do vaguely remember 6 speed cars being somewhat tough to find back then. There's still no 94 with M29 nor M28 ratios.

 

 

Incase no one has seen one.
T5 on left, 91-2 Firehawk bellhousing for a ZF 6speed and a 89 TTA trans crossmember under the Hawk bellhousing