Originally Posted by my93Pathfinder

Are you talking about the Sentra Spec-V? That's a 4 cyl.
If you want the most power with the easiest (I say 'easiest', proportional to the amount of power you get) set up, then you could find a VG30ET from an 84-89 300ZX turbo. It is the same exact 3.0L V6, except it has a turbo, good for producing 205HP and equivalent torque. Plus, if Nissan didn't screw with the block bolt patterns, it should bolt right up to your frame and transmission. If you want more power, just add a boost controller and crank up the boost. Since they came from the factory turbo'ed, then they should be able to be tuned for more HP/TQ. I've pondered that swap a few times myself, but am not sure about the 'direct bolt in' aspect. Let me know if you do decide to do that.