Final judgement....T 5 strength

I have now a real world´s experience about how much a T 5 can take.Here´s the story.
I had a lot of trouble with my C 4. Some years ago I bought a new Z 7003 T 5 along with billet flywheel and Motorsprt King Cobra clutch & Power Tower shifter. The engine was a full treatment street 355 W ( Ebrock Performer cam/intake 600 Holley, ported GT 40 heads etc., abt 330 horses).9" rear with 4.11 gears, only driven with radial street tires .
The trans and the clutch were ok the 2 first summers, driven appr 3000 miles,sometimes very hard I admit. There was some gear whine on 3rd and a steady hissing sound on 5th already from the beginning.Last year I changed the cam to a hydraulic roller( 224 deg / .566 I &E), changed the intake to a Stealth, a 750 vac Holley and ported the heads more.There was now appr 400 horses.Took the car to a dragstrip where it did 13.01 / 108 mph on standard radials. on a very hot day.At the end of the summer the trans/shifter started to make very loud buzzing sound above 5000 rpm or so.I just kept driving it though.
Last winter I built a new 393 with around 500 horses.The trans took it about a week or so, then I needed to take it apart due to excessive buzz and vibration, which felt like loose bearings. Took the trans apart and all the tapered bearings were loose, there was too much end play.Shimmed the bearings tight again and 90% of the problem was gone.
Then I had this grand race with a Kawasaki Ninja where I drove about 4 miles on 5th with the pedal floored...well above 150 mph all the time. After the race the trans started to make loud gear whine on all gears except 4th( straight gear).Also the buzz and vibration is partly back.
My conclusions: T5 is not a real hi- performance trans. The case is too weak to withstand the axial forces a powerful engine produces.Also 5th gear is way too long for hi-speed motoring & acceleration.
Based on my experiences I would not put a T 5 in a car which has : more than 302 ci displacement, 350 horses and 3000 lbs of weight. The trans does not explode but it gets very loud and vibrative.
I am going to get a new trans for next season, perhaps a Tremec TKO or a 6 speed T 56.
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Putting a little T-5 against a hi-po 393 stroker......[img]/phpBB/images/smiles/icon_eek.gif[/img] Shame on you!!

What did you use for lube?

I used Redline MTL.
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Lets say you're like me, and whatever you drive, you want it to be a manual, what is a "step up" from a T5? Or does it just have to be race prepped/rebuilt with stronger parts?
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go with the tremec 3550 or tko

only thing is hard to find!

Sounds like u need a t56, thats If you plan to keep on racing Ninja.[img]/phpBB/images/smiles/icon_biggrin.gif[/img][img]/phpBB/images/smiles/icon_biggrin.gif[/img][img]/phpBB/images/smiles/icon_biggrin.gif[/img][img]/phpBB/images/smiles/icon_biggrin.gif[/img]
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As the old saying goes, some people can tear up an anvil with a handful of feathers!

Yeah, true ...on the other hand some people never have an anvil or feathers to give it a try...
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Just saw this at moderndriveline.com:

One last piece of important information. ALL T-5 use ATF oil and NOT heavy gear oil or Redline MTL!

Maybe the Redline MTL didn't help your T-5 any?

Robert