It is possible to put twin turbos on a 1995 3000GT, but it is not a simple or inexpensive project. The stock turbo system on the 3000GT is a single turbo, and to add a second turbo, you will need to purchase a new turbocharger, a new exhaust manifold, a new intercooler, and a variety of other parts. You will also need to have the engine tuned to work with the new turbos.
Overall, adding twin turbos to a 1995 3000GT is a significant undertaking that should only be attempted by experienced mechanics.
