[Streetwize]

Opinions vary but I think the torque rating of transmissions and clutches alone can be a poor way to choose, the issue to me is they have to design transmissions for a wide range of vehicles, and (for example) a 3800+ pound 60's muscle car is going to put a lot more instantaneous shock load and continuous drag on the gears and synchros in that transmission and on that clutch than the same motor would in a ~2500 pound Cobra. I would put vehicle weight as the first factor to consider, how abusive you intend to drive it would be second.

You would have to be launching a Cobra on a pretty steep incline to even remotely simulate the instantaneous shock load that a ~50% increase in weight would subject that transmission to every day in terms of endurance and strength. Cobras are very easy to get moving and keep moving by comparison.

Something that GM is notorious for is putting a comparatively weak clutch in their performance cars, but if you think about it it's pretty clever, the clutch after-all is the replacable "fuse" in the drivetrain. Actually the tires are the first thing to reduce engine load, the clutch would be the second.
it's similar in some ways to having 8000RPM valvesprings in your 6000rpm redline engine, overkill you'll never really subject it to.

I have the standard Tremec 3550 (non TKO) in my 500+ HP 427" Windsor stroker along with the Ford motorsports (5.0 Upgrade) clutch. Works absolutely flawlessly, shifts very smoothly and it has for the past 17 years or so I've been driving it. My only complaint would be I think there is too much of a gear ratio drop between first and second, I'd prefer maybe a taller first gear.

I've been drag racing for over 40 years and I can (and have) shifted cars much harder and faster than I reasonably will allow myself to in a Cobra. not because I can't it's because IMO a Cobra set up for proper/optimal handling will not track straight under a full throttle launch and a violent 1-2 powershift. And to set the car up to optimize a Drag launch won't handle very well.

An old Porshe 930 Turbo is very similar in a lot of ways in terms of the "potential vs optimal" launch, just my opinion.