Possible to weld a grande lsd?

Rookie question, but I've heard of people welding viscous Lsd's and iI've never actually had a look inside mine.

I'm sure it's possible but I'm sure someone with a stock open diff would trade plus cash for your lsd

Anything's possible. Cressidas use clutch type LSDs.

+1 Trade+cash for someone's open and weld that.

In 14 years of importing stuff from Japan, I have never seen a viscous LSD in an X-chassis.
You probably either have a worn out clutch style LSD, which can be rebuilt, and upgraded for cheap,
or you have a Torsen, but they don't go bad unless you break one with 500+ hp.

What is your 'trans/axle' code on the vehical ID plate ?

If it is the clutch LSD, it doesn't take much to improve them.
Weir Performance sells a spring spacer, and a booster spring that doubles the holding torque.
Also, the cressida LSD is assembled from the factory to lessen it's holding capacity, instead of one inner plate, folowed by one outer, one inner, one outer, etc.,
the cressida had 2 outers, followed by 2 inners.
Just pull it appart, change the assembly sequence, shim the spring, and it will suprize you how well it will hold.
Jst don't mix up the bearing shims when you reassemble it, as they are select fit to get gear mesh correct, and if you mix them up, then you will have big problems.
So just keep track of which is which.
I just throw each in a plastic bag, along with a note of if it's the left, or right.