Your diff is more likely to break first

T series boxes do break...... I have trophies to prove it
But it is rare so I am lead to believe
I am probably changing to the stronger steel case soon as an added safety margin

3T has 22 output splines
2T has 20 output splines
both have 21 input splines on 23mm shaft

both have 7 bolts holding bell housing to the box and are split alloy cases.

I memory serves me correct the box is known as the T50 split case . There are two variants of this box, 2T and 3T. The 3T was the variant that was fitted behind the larger capacity engines.

as alredy said, you wont brake it any time soon. the box that you have is a t50 (i recon). they are rather strong. i have a t-18 paddock thrasher it has the same box, done close to 400,000kms the engine dosent like to rev much but the box still works... if thats any testomony to its druability.. would win me..

cool what kind of motor do you run in your race car? and where do you run it? i love to see old dattos serve it up to the big boys.

Toyota make one of the best production boxes in the business. I would think something else would give up before the 3T. If you subject it to continual shock loadings [dumping the clutch] I guess it would eventually fail.

I use a 3T in my racecar, and it is still going after 5 years of abuse.

Howdy Y`all, I have just finished phase one of "project 4x" (four x std power) in a standard `67 1000 2dr.
I pulled the motor from my little redwagon ( a15, t03 turbo ((same as vl)), 1.75 stromerg carb, water/meth, 30 psi ??kw, 17psi 105kw) and put a shiney new dellow 5 speed behind it, unknown prop shaft, and a BW 120y back end in.
I set the boost at 10 psi for the initial shake down (no water/meth, and i didnt want to break my new 5 speed) no probs.
This weekend I fitted water/meth, wound the boost up to 17 psi and adjusted the clutch the only prob was that the little 155/80/R12 chesse cutters tend to let go above 4000 rpm.
I still have to put in the welded diff from the wagon and fuel pump (holley blue) then wind the boost back up to 25-30 psi.
Do you rekon the celca box will handle it. I had a ford cortina 4 speed in the wagon and it never had any probs?