Replacing Uni Joints

Hi
I have just installed new unis in my tail shaft.

Q1 If I install the unit back together the same way, Do I need to rebalance it?

Q2 How are the Diff to tail shaft bolts secured, do they use any loctite, or just tension the bolt? If so how much. I was planning to use a flat washer and a bit of loctite.

TIA
Emil