Will a 3000gt vr4 motor fit in a 1995 mitsubishi eclipse gst?

Not without some modifications. The non turbo dohc 3000gt is essentially the Vr4 just without twin turbo's, awd, 6speed transmission, an other turbo essentials.. consider the fitment of the engine 1st then take into the equation of the turbos, manifolds, transmission, etc.