Are you re-using the cooler or using a new one (possibly the one that came with the i7-3770) ? If you are re-using a cooler, you will need to clean the thermal paste off of it and apply new paste. For the cleaning, I use 91% isopropyl alcohol, commonly available in drug stores/pharmacies/chemists (for our UK friends). New paste can be obtained from where you're getting the new CPU, or from a local computer store. If there's a Radio Shack near you, it probably has AS5.
Edit: Unless you were redlining your existing PSU, the power-draw difference will not require a replacement.