A rebuilt T-5 is no stronger than a stock one, and the same with a "world class one." I didnt say TKO 500 or 600, i'd say a used 3550 or a TKO would be better off, you can make a t-5 live is you are really easy on it, but any kind of angry driving its not gonna last, plain and simple, a friend of myne has been thru i think 3 rebuilds on his T-5 before he smartened up. The last time it broke the car was in 2nd gear, it didnt even break shifting. He has just as much invested into t-5's as he does his liberty faceplated TKO600.
Im just trying to help you out, i dont know how u drive but if you like burnouts, donuts, or powershifitng, the T-5 is not a wise choice in the long run... yea its cheaper to rebuild what you have, but for 1000-1500 bucks you could swap a TKO in and have the piece of mind of not being scared to really drive the car.
But if your gonna just cruise around and not race the car stick with the t-5