differential

[3154tm]

as part of an engine swap and drive train upgrade
i'm trying to find a suitable replacement diff for a
2500M. the natural choice would be a salisbury, but
those with lsd are scarce on the ground here in the
states. i'm now looking at the nissan R230 which came
in the infinity Q45, some z cars and perhaps others. Goodparts offer a kit to put this diff in a tr6 which
might work in an m chassis. the problem is finding out which ratio and which type of lsd came in which cars. anyone have any insight on this topic.
frank