I was thinking about putting together a relatively economical, genuine AWD car.

I wanted to use a 2000 or 2001 USDM Impreza 2.5 RS 5-spd. as a basis. As you probably know, this came with an open front differential, a center viscous LSD and a rear viscous LSD.

I wanted to add the viscous front differential from an early nineties WRX Type RA. Several sources indicate that they came with a front viscous diff.

This is not to be confused with the SureTrac cam-and-pawl type diff in the New Age Imprezas (even if SOA at one point mistakenly referred to them as "viscous"). For one I don't think it will fit in the 5-spd. tranny. I am also not talking about a Quaife.

Actually, I am partial toward a viscous coupling. Viscous couplings have worked well in rally and F1, they work when one wheel is suspended in free air, their progressive action means that they don't cause much initial understeer, and they are maintenance free.

1) Can anybody give me the part number for the viscous front diff for a GC-8 (or sell me one)? Or maybe there are several diffs, depending on the axles used? I wouldn't want to change axles if I could avoid it. The viscous diff is not in the STI catalog.

2) Does anybody know the rating (in kgfm/50 rpm or Nm/50 rpm)?
Also, what is the rating of the standard REAR viscous diff with the R160?

3) I have heard that Subaru parts people can only look up parts for a vehicle if they have the VIN. Is this correct? For some brands, e.g. BMW, you can find parts catalog CD-ROMs on ebay, but not for Subaru. How come?

Thanks in advance,
Dane in Balto