Long story short...

I've been running my WRX with a R160 with a cusco plated diff (4.444 final drive), i've used this setup for a while and im now on my fifth differential.

All the differentials seem to be fine when they are installed but over time each one starts to have the same issues with whining after around six months to a year.

I am considering an upgrade to an R180 (4.444) diff , from my research and advice from dtrally (thanks Doug). I'll be needing a few other parts to make it all work.

5x100 rear hubs from a STI (01 - 03)
R180 Diff from a GC8 Type RA (4.444)

My question is, should i be sourcing R180 driveshafts from a STI (01 -03) also?

Is it worth making up hybrid drive shafts to allow the R180 diff to work with R160 hubs? (guessing strength will be a big issue)

Advice?