[blykins]

I wouldn't trust it.

I've known people that broke them with factory 215hp 5.0 Mustangs.

If you have the option/budget to upgrade, I would advise you to do so. The T5 is rated for around 300-330 lb-ft of torque. Now granted, a Cobra may be a little easier on a trans than a heavy car and wheelspin is abundant, but if you ever get it spinning and it hooks up hard, you will lose the transmission.