Auto Parts: 98 blazer 4x4, rear differentials, gear ratios

Question
I recently changed my motor %26 trans (same time).pulled used motor%26tran from same 98 blazer but wheel size was different(?). transfer case and/or differential was different. runs %26 drives good but 4x4 clanks and does not work right. Q: can i change gears or something in my rearend rather than pulling front end to take transfercase out ?  

Answer
    With four wheel drive it is essential that the gear ratios in the front and rear differentials be exactly the same.  Obviously yours no longer are.  You can change either one, and there is just about as much work involved in doing either one.  It might be easier for you to do the front, since you are already familiar with working on that unit.  You are going to have to take both covers off and count the teeth on the gears.  This will give you an idea of whether or not they are different.  If they are the same, then something else is wrong.  If they are different, then one or the other needs to be changed to match.  But you really should look inside both, regardless of the difficulty, 'cause that's the only way to tell for sure.  And, if you don't fix it, something expensive is going to break.