Weddle Engineering.
Two year warranty, unlimited miles, cost $895/$400 core.

I had a problem with a locking diff that I had them add, they applied the
cost of the locker to a four spider German heavy duty diff and did not charge
me the labor to fix it.

I started looking for a taller .091 fourth gear and ended up with a new five
speed gearbox.

Talk to Chris.  They stand behind their work.

Just a happy customer.

Robert