Auto's run fluid through the radiator for cooling, so different radiator.
Autos need the kick down set-up installed on the carby.
May need a different tailshaft.
Not sure if the cross member needs modification. Perhaps check digital corvette or corvette forum.
Will requiring re-wiring so that the car won't start whilst in gear. I have bypassed this going from auto to manual, but I'm not sure how it works going the other way.
T400 (and T350) are a mechanical (non computer) 3 speed box. Both are fairly tough, and are stronger than the T700.
A T700 is also referred to as a 4L60 or 4L60E. E = electronic
The T700 is a 4 speed box and was used in commondores and C4 vettes. VN's used a non-computer controlled version. Later commodores and C4's used an electronic version. T700's have a lock-up torque converter which can be tricky to incorporate, depending on who you ask. I can't remember exactly, but if you don't do it right top gear will burn out or break. A T700 will require modification to the cross member to make it fit.
A T700 will struggle to last behind a 502 rat :)
I may have researched this subject previously :hammer: