bravada axle swap

I installed bravada tube and shaft in my 97 blazer, I got everything back together and now have leak from other side seal, I think. I'm trying to check 4WD function so I tried driving in a snow covered parking lot but could not tell for sure if front tires were spinnin. I saw spin-out marks behind rear tires but not sure about the front. I had my girl look at passenger's side wheel while I gave it moderate gas but she could not tell. We'll try it again tomorrow and I'll have her look at both sides. Should both front wheels spin in 4HI, or left or right one or a random one, like the one with less traction? I jacked front right (passenger) wheel off the ground while in 4HI and car idling and in park and right wheel would not rotate. Does this confirm that it is in 4WD? When I pushed button to put it back in 2HI, the wheel still did not spin around. Is this because I now have the AWD axle in? I still plan on changing that seal, but just trying to determine if it is really in 4WD first. Thanks again for everything, This is a great site.:)