GVX

I want to do a SA swap on my 1995 Hi-lux it has a 5.7 chevy with a toy 6 cyl 5spd 31.5 tires 4.10 axle ratio I have found a 1994 landcruiser with 3.70 axles ratio's I think they are 9.5 ring and pinion's can these be easily transplanted into my pickup and do the SA swap? I want a lower gear as I have sufficient torq with the V8 I am turning about 2900 RPM at 70 mph right now this will help with fuel economy I think droping my rpm to maybe? 2400-2500 RPM