Although the ratios are the same, there are T5's and then there are T5's.
Here is a link to the ratios and torque specs for the different models.
I would suggest a minimum torque rating of 300 ft.lbs., the Y is a torquey engine.

http://moderndriveline.com/Technical_Bits/transmission_spec.htm

A bit more info (WC is World Class, more info here  http://moderndriveline.com/Technical_Bits/t5_history.htm )

GM WC About this time (1990) GM entered the WC T-5 with the S-10 and Camaro T-5. Borg Warner produced both a 2x4 and 4x4 T-5 for the S-10 with different gear ratios depending on motor type. The 4x4 model was connected directly to the tranfer case with a short main shaft and tail shaft housing. GM used the T-5 in both the V6 and V8 Camaro’s, but the gear ratios were different, as well as, the bellhousing to transmission bolt pattern. The V8 Camaro received the same bolt pattern as earlier four speeds but with a 22 degree rotation to place the shifter closer to the driver. It is believed that GM changed the bolt pattern of the V6 T-5 so that it couldn’t be installed behind V8 motors. From looking at the outside of a Camaro T-5 it is difficult to tell them apart. GM used the WC T-5 2.95 gear set only in 92-93 IROC Z Camaro’s. In 1994 GM switched to the new T-56.

The bold is from me.

Good luck, post some pics and keep us informed of your progress  




South Australia

Cheers "slick56"...good info right there....

After days of researching the many ways in which i could of installed /modified the internals of a Vn T5....as finding a mustang T5 or even one that is not over the $2000 mark in Oz is a task...
I think i will just stick to the Standard 3 speed that came with the 292 out of a 1956 ford f100.

because the last thing i want to do is spend all that time and money on the T5 only for it to break under the torque of the 292...


But cheers for everyones help in info 

Unless you are drag racing the T-5, it should live quite well behind a 292.  I have the T-5Z behind a 351W +040, 3.750" stroke for 385ci, and it had been driven on the street for years, and raced occasionally with drag radials.  I also have another stroker 351W +.030, 3.680" stroke and 14psi boost with "Z" trans that has gone as quick as 9.82 @ 141 mph in '88 GT with AC, PS, roll cage, etc.  I have a daily driver 91 LX with "Z" that has been on the rollers with 293hp/303tq to wheels.  The stock T-5s will not last long with abuse, but don't give up on the idea, since the newer upgrads will live quite well on the street if you do not use slicks.  JMO, but I have driven the "Z" transmissions since 1988 in Fox mustangs.  Broke axles, but not transmissions.  Joe-JDC

JDC

Just to let everyone know, my WC T-5 out of an 89 Mustang has stood up surprisingly well behind my basically stock 292. This is also with a stock 10" clutch (which also survived quite well) considering how I drive my car! Everyone who knows me will tell you I drive my car like I stole it! I even snapped my 9" housing in two, but the clutch and tranny, no problem! I leave the line at about 3500 RPM on a clutch dump and shift it right up to 5500 RPM (I get rubber right into 3rd
!). 
It will be interesting to see how it holds up, now that I am building my Y with a Mummert Performance engine kit!!!!!



I love the smell of burning rubber in the morning!

Forgot to mention, my T-5 was a $500.00, junk yard special!!! 

I love the smell of burning rubber in the morning!

I still go a T5 gearbox if i could find a mustang one here cheap enough....but mustang parts especially gearboxes are a pretty hard find in sydney .that arnt way over priced

That's a shame, because I LOVE my T-5! Car comes out of the hole sideways due to that 3:35 to 1 first gear and I have gotten over 27 MPG in 5th due to the .64 overdrive!   



I love the smell of burning rubber in the morning!

This was my initial test drive when I installed my T-5   

I love the smell of burning rubber in the morning!

haha awesome vid..
was that with the mustang T5z gearbox ???

Earlier in this thread I suggested you read the Modern Driveline article that delineates the development of the T-5 since 1980. The point of the article was that ALL T-5s are NOT the same in their design and construction. There have been engineering changes that make some T-5s better choices for putting behind a Ford y-block than others. While how you drive your vehicle is a factor, the torque output of a Ford y-block makes some T-5s a bad choice for reliability and service life.  There's nothing wrong with sourcing a T-5 from a salvage yard, but you want to know what vehicle to take it out of... 

Here's a piece of that Modern Driveline article...

The "Z" Spec T-5

In 1993 Ford started offering a new service unit to the Ford Motorsport crowd. The nick name T-5z comes from Ford’s part number, 7003Z. The T-5z is best described as a 1993 Mustang Cobra T-5 with 2.95 first gear set and .63 over drive. It has the best of everything. Hardened gears, short throw factory shifter, steel front bearing retainer, and tapered output shaft bearing and a seven tooth drive speedometer gear. Best of all it has a torque rating of 330ft/lbs. based on 100,000 mile usage. The stock T-5Z can handle up to 450hp with a soft locking clutch and is not shock loaded like in drag racing.
_______________________
Just as all FoMoCo 239, 256, 272, 292, and 312 y-blocks are not the same, not all Borg Warner and TREMEC T-5s are the same.    

NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York