Hi I'm also building a S13 VH45. Nice to see your almost done.
In regards to the diff. Sell it now. I'm not sure if you have aspirations of drifting but i think the 2 way is overkill. The 4.36 ratio is a terrible match for the engine.
If you want a budget baller setup.
Sell the following:
Diff
Driveshafts
rear 5 stud. (will still be 5 studs after but larger spline count. q45 or 300zx rear hubs)
You should be able to get at least $700.
Then put in a r200 from a Nissan q45 and drive shafts.
WHY???
Well the q45 diff ratio is matched for Vh45
The q45 diff is the strongest r200 diff that nissan make. They have ultra beefy drive shafts. Extremely thick with a much larger spine count. Unbreakable and will take 1000hp easy
Sure they are a viscous lsd. BUT because they were fitted to luxury cars they are in perfect condition and you can always change the center later.
This is a popular swap in the US because of the fantastic condition of the units and the fact that they are indestructible.
If you want this setup I have a spare from my build. Will let it go for $399
Includes diff and shafts.
If you want some info PM me