The term "need" is kinda being used liberally for tranny stuff. You dont "need" to do any tranny work in order to run those numbers, but the chances of breaking something increases with power. Not saying you shouldn look into it as you should... but know you can run fine on the stocker as long as you dont drive like a jackass.
now if you do end up going to the turbo type stuff... thats a whole new story.
I only have a shift kit in mine and haven had a problem yet (knock on wood).
You could listen to this guy and then be breaking it later and without a car. You have the labor free... use it.
98ChainStretcher broke his trans with a 2.8 setup, some other guy broke his input shaft on the 1-2 shift right after he finished tuning.... Your building the car to drive it. So drive it.
Personally I didnt build one right away beacsue of A) Money B)Time but now I went crazy and build a hell of a trans