exactly the vg30dett is meant for the boost just like you cant just throw the boostat a vg30de its a different engine
the 3.5 is an awesome engine award winning infact nissan has always built great v6s but yeah go vg for sure the vq will blow up
besides not for sure but doesnt the vg30dett give the 240 a 50/50 weight distribution
the only reason a 3.5 would make more power is the high compression
and the increased displacment but its not going to do it for long