omg im agreeing with newman, the world is going to end.
While it’s cool to be different, it’s not always the best thing.
Before anyone can give you any real advice, you need to let us know what you want to accomplish with this car.
Do you want to drag race it?
Do you want to make lots of power?
Do you just want to be able to say, “I swapped a V8 in there!”… ?
Etc.
Built bottom end, single turbo, while its not the most origanal its the best on these cars.
Wrong reason to do it.
You will spend 30-40% more even if you have connections to source the engine.
What supporting mods do you have done to enable your FWD car to use the power from a Northstar or a supercharged N/A ? Add a couple grand for that.
With the amount of money you will end up spending, you could sell your car, take the 6-8K and buy a platform better suited to modify.
I spent a good 5+ years with the 3S platform. I started with an NA and then sold that and bought a RT/TT and modded the hell out of it. From the research that I’ve done and years of experience I can tell you that unless you plan on spending wayyyyyyy more then what you want to spend, you’re not going to accomplish your task. In my opinion, Sell your car and buy a TT if you love the 3S cars so much. In all honesty, there aren’t very many well modded Twin Turbos out there and the ones that are can be a ton of fun 
If you want to do something different or have the wow factor, sell the 3kgt and get an rx7 with a blown motor and put a V8 in it. But think of how many Twin Turbo 3’s that you see in Buffalo…its not a lot.
thanks guys, ur input was helpful. I think i might start looking for an rx7 ive been doing some research and it looks exactly like what i want to do. Im still going to keep my 3kgt, and will most likely supercharge it, i just have to decide what type im going to do. As far as trading up for a TT ive been looking for a while but dont want to buy a first or sec. gen im looking for a 99 or a vert. which i havent found one i like. but thanks everyone u really helped me out.
best advice -
3000gt can look cool…make it look pimp and be happy with it or
get a RWD platform before you waste too much money to be…sorta quick and never hook up
Buy a RX7 and sell me the 3000, Ha Ha.
what are you planning on doing to an rx7 
i dont think that a nissan v8 is the easiest thing to come accross
seriously tho i have realized my 3000gt is going no where so i have spent nothing on go fast parts, was considering a fwd tt conversion which everyone does with success but its still fwd. so my advice would be to get a vr4 if you like the platform!
There already is one in the area 
Q45 motor. Not too hard to come by. They can make crazy power, when boosted.
http://cgi.ebay.com/ebaymotors/89-92-Infiniti-Q45-4-5L-V8-VH45DE-Engine_W0QQitemZ300075306022QQihZ020QQcategoryZ33615QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
there’s one for 750.
It’s not done yet though…
Yeah but he’s close - shooting for Winged Warrior. :tup: