Nissan Repair: LSD install 1994 Pathfinder, gear ratios, rear tires

Question
I just installed rear LSD today off a known good vehicle, both have same gear ratios'. While I still had it in the air I spun the rear tires just to see them go in the same direction. When I tried to turn the wheel it was real hard to do, it took both hands to do it and then they stopped right away. I remember doing that before the swap and the tires would spin easily. I took it for a road test and I could feel resistance. Meaning it took a little more gas to go forward. While cruising there is a low vibration sound coming from the rear. Also, while cruising if I release the gas it slows down noticeably.
I was thinking maybe the axle ends need to be shimmed out some. Is it possible the axles are squeezing the 3rd member too tight?  

Answer
Rich,

I would not think it was the axles being too tight.  You could shim them and see.  But, my bet is that the differential is binding.  I would remove the differential and check the tolerances.  Since you say it was off a known good vehicle?  I would get a factory Nissan manual along with a dial indicator and mount to check lash and such.