t-56 would do it, and it would be a lot quicker than with a 5 speed because of the closer ratio transmission gears. thats the transmission im wanting for my cobra when i get my 347 stroker and h/c/i done. the stock t-5 would last for a little while with a smaller head setup but im gettin afr 205's which will put me at around 525hp at the flywheel and that would blow the t-5 to pieces. or you can look at the tremec tko500 ot tko600, those are both good 5 and 6 speed transmissions that will hold a lot of power.