does anyone know if there is an LSD diff that will fit into a C20 housing at all?

Depends on what kind of C20 housing it is (C20 is early Vanette, right)?

If it has a H165 housing, see What Diff and LSD?.

as far as i've been told the C20 housing is supposed to be the same as bluebird and R31 skyline which is also supposed to be the same as falcon, but only if its the borg warner with the lift out centre. ie, from the front. i have an lsd from an EB falcon but so far haven't had the time to try and fit it. but i have a vanette housing which is supposed to be the same. i got the centre for eighty bucks, but needs new clutch packs.

Squiggs I think you have been told wrong. The Falcon Borg Warner type 75 is a Salisbury style rear loading diff. Aussie market Nissans (Skyline) got them too but the C20s has H165 or H190 Nissan banjo front loaders. C20 A12s had the 165s and A15s got the 190.

The A15 would be the C120, wouldn't it?

OK to answer my own question:
C20 - 1970-1978
C120 - 1979-1985

The C20 was named various things: Datsun Sunny Cab, then Nissan Cherry Cab, then Nissan Sunny Cab.

The C120 was called the Datsun Vanette or Sunny Vanette or Largo.

Quote:

Well, not exactly, it's a little more complicated...

I bought a C120 once for the diff, hoping it would be a 4.875:1 H165 LSD. It had a Z20 engine and was like a velour lounge suited livingroom on wheels. The diff was about 6 inches or something wider than the stock 1200 diff, (Makes sense that it was called a Largo I guess...) 4.11:1, and non-LSD.I swapped it with a wrecker for a C20 diff, which was about 4" or so wider, H165 4.1:1, non-LSD. I have also seen H190s in C20s as stirlingmac mentioned.

Feral has a very useful microfiche that he has posted before about what axle/ratio came in which vehicle, if someone more computer savvy could dig it out it might be helpful?

Like anything to do with Japanese cars, it's a whole lot more complicated than it first seems...

And to answer the original question, yes LSDs exist and are available new, but are quite pricey, around NZ$1300+ gst and shipping ex Japan.
There are rare as hens teeth secondhand, although rally-a-coupe posted recently that he had one in a disc braked housing for $1500. I PMed him asking if he still had it but haven't got a reply.