Help!! Engine swapping a 2.5L for a VQ 3.5L

my engine block cracked when me radiator blew up in my 02' altima and i was thinking instead of trading in my car i might as well upgrade the engine, can anyone give me suggestions, if it is possible to mount the vq3.5 on the same mounts as the 2.5L and if i can use the same tranny and ecu?
any ideas? comments? all will be considered thanks