vlsd guts swap into non vlsd housing

[tastyratz]

So I have been doing lots of reading over the last few days and getting a ton of conflicting information of all kinds of vintages that *almost* fit (such as j30, etc)
I wanted to clarify. There is prettymuch nothing solid on straight 240 pumpkin to 240 pumpkin transplants.

I have a standard s14 pumpkin pegleg open diff in my DD.
A local guy put an s15 diff in his 180sx vlsd housing so he sold me the vlsd heart transplant.

I have 0 experience inside the diff. I can hand build my engine but just haven't cracked open a diff yet.

Can this literally be a straight drop?
Will I or will I not need vlsd shafts?
Am I going to need to shim anything (where do you even buy shims anyways?)
Any tricks I need to know? (loctite, torque specs, etc)

And just curious, how long should I set aside for the breakdown of the diff? anything else I will need (any tty bolts? liquid gasket ok?)
God I hate being the n00b.