There are a lot of factors on that question. The weight of the car, flywheel weight, clutch style and rear gearing. Then the other things are the hp and tq. the engine makes, then exactly which gear set you have, meaning which gear ratio set you have, then what style they are, then who made the gears. THEN ONE OF THE MOST IMPORTANT THINGS AND MOST OVERLOOKED THINGS IS HOW THE TRANSMISSION WAS BUILT AND IT"S CONDITION.
A lighter car, with a light flywheel such as a aluminum flywheel or stock 5.0 iron flywheel, should have less energy and less potential to damage a transmission, when launching the car at high rpm. The clutch design, base spring pressure, clutch disc design and material. A diaphragm pressure plate will have the highest base spring pressure and will shock the drivetrain the hardest. A long style clutch like a Ram 9000 series or McCleode Soft Loc will have lower base spring pressure and will allow slippage when the clutch is initially released, so the drivetrain is not shocked as hard. Then clutch disc design and friction material is important. You do not want to use a solid hub disc, you need to use a sprung hub. Then a friction material that is not overly aggressive. Kevlar discs are usually a bad idea for drag racing with any combo, the pucks will melt.
Then the transmission it's self. There are many different factory gear sets, with different torque ratings. The later factory 3.35 first gear sets are some of the better factory gear sets. The Cobra style pocket bearing gear sets are supposed to be good for more hp, some people disagree, but I have used the pocket bearing T5 gear sets to go very fast. Then there are the 2.95 and 3.35 1st gear ratio gear sets, with either the common torrinton bearing design and the cobra style pocket bearings. The Borge Warner gear sets seem to be the strongest from my experience, fallowed by the Tremec. Then there are aftermarket replacements for the factory gears, some of those are much weaker than either the Borge Warner or Tremec.
Then you have the G Force and Astro gear sets, those are very different from the factory gear sets. They have wider gears, with thicker teeth, less helix or straight cut gears. They also sell stronger output shafts. These parts are much stronger than the factory Borge Warner designed parts.
The biggest reason T5s break, is most are too loose, too much end play, either a result of years of wear and tear or being built improperly. I built a T5 that I used in three cars, the first one was a 12 second 85 GT, that I ran at the track regularly. That is actually the car I used to figure out what the problem was with the transmissions. I built a T5 that did not loosen up, it never loosened up after years of trips to the tracks on slicks. I then pulled that transmission and installed it in another car I built. That was a GT hatch that went high 11s, that car got totaled. So I built the car I have now. I put the same T5 in that car, most of the time the T5 was in that car, it ran mid to lower 11s. The last 306 engine combo I built that I used that T5 behind, made 418 whp, ran 11.02 at 125 mph. The car ran a best of a 1.49 60', with that transmission. I first built that transmission in '97, I ran that transmission till '06. I never broke a single part. I originally built the transmission with a pocket bearing style 2.95 1st gear set. That is the gear set I ran the longest in that transmission. I figured out the car could run quicker with a 3.35 1st gear set, so I swapped the gear set out, sold the old 2.95 gear set to a guy on this forum. I ran the 3.35 gear set for about three years, before I built the engine that is in the car now and switched to a C4 which was a huge mistake, I hate autos, they seem to hate me also. The only problems I ever had with the T5 was at one point I was not able to get Kevlar blocker rings. So I had to buy carbon fiber blocker rings from a local transmission supply shop. Those blockers would only last three passes, then I had to pull the transmission and replace the blocker rings. The Kevlar blockers would last me years without problems. It turns out the blockers I was buying were cheap junk, but at the time, they were all I could find. I finally got tired of replacing blockers and had the transmission Pro Shifted. I never had any problems at all after that, it would shift so fast people thought I had some special race 4 spd auto trans.
The Tremec TKOs and TKO 600 transmissions are definitely stronger, but they are very notchy, when they work correctly. The older TKOs usually did not have shifting problems. The new TKO 500s and TKO 600s have multiple problems that make them hard to shift at higher rpms. There are kits you can buy from Liberty gears that will fix the problems, but for what Tremec charges for their supposively superior transmissions, they should shift as good or better than a T5. They don't, when they shift the best possible, they are notchy.
So there are trade offs, either a good shifting transmission that if not built correctly, can break or a transmission that most likely won't break, but likely will need some parts replacements, to get it to shift at WOT.
If I buy a part or parts from you do not send me those parts through USPS, I would actualy like to get the parts I purchase.