Engine swap V6 to V8
 

I have a 2002 GMC Sierra Pickup with a 4.3 automatic 4x2 standard cab with an 8 foot bed and I am looking into swapping out the V6 with 270k miles on it with a 5.3 automatic. Would a 5.3 along with its transmission be comparatable with my truck? Meaning is there any major modifications needs or is it and easy swap with minimal modifications?