I have always thought it would be awesome to do that, but snwbrdr435 is right. I checked on the price and it looked to be almost $15,000 in parts alone. Once you get the motor you have to do (depending on the motor) either a RWD or AWD conversion. Lots of $$$. You should do it though.

Personally... I don't think the RB is all its cracked up to be. I think your stock VQ is a much better engine. Why? Inexpensive, very light weight, compact, and strong. It doesn't get much better than that. Those are some of the reason why they replaced the coveted RB26DETT in the JGTC R34 Skyline race car with a turbocharged VQ V6... which made for a faster car.

Don't buy in to all of the RB hype, not only would be it very expensive and next to impossible to do in a front wheel drive application... there would simply be no point other than to be unique... but that's a hell of a lot of money to simply be unique.

If you need any large items shipped like engines or even front clips, I can help you out. Just go to AssociatedShippers.com and get a quote.

For a car like that though, I'd do the DOHC RB30 setup (something like an RB30 block with an RB25 head I believe). The RB30's have a slightly longer stroke than the VG30's so they would probably be torque monsters and would move a larger car like the old Maxima really well (not that the RB25 couldn't... its just that you'd be revving to make the power whereas an RB30 should have great low end power which is nice on the street and in heavier cars).

edit sorry if that doesnt make sense friends 21st birthsday today.

The G35 is the Skyline with the VQ.
Unfortunately, the RWD and FWD VQs are quite a bit different and not interchangeable.

4.08 VLSD, NICO 8-way ECU, full exhaust with custom headers,
Tokico Blues with Eibach springs, Stillen FSTB, 20mm RSB, 255 rear rubber.

Now, I believe Stillen used to make a centrifugal supercharger kit for the 4th gen Maxima's but they're no longer in production to my knowledge so you'll have to search for a used one.

Internal wise, you don't really have to change them out as long as you keep the boost relatively low and tune it well.

Personally, I'd probably go with a turbo setup instead. It takes more fabrication to pull off but they just tend to perform a lot better than superchargers. The screws s/c is pretty much the best one out there as far as power and efficiency goes but they've been pretty unimpressive on the Z's from what I've seen. They do offer quick boost but a good turbo setup can still easily outperform one.

The centrifugal superchargers, like in the Stillen kit for the Maxima, are pretty efficient but still suffer from "boost lag" in that you don't have instant boost like the roots and screws superchargers and boost is linear... meaning, you won't have peak boost till redline since boost continually builds. This is the centrifugal s/c's weakest point in my opinion. If it were able to hit peak boost early and keep it there till redline it would probably be the best option out there but as its unable to do that, the turbo still shines.

In the end, it really just depends on what your goals are. How much power do you want? If you just want a slightly faster car but aren't looking for a ton of power the centrifugal s/c and turbo would be a good choice. If you're wanting to make a lot of power down the road the turbo would be best choice.