well whatever year the 4.37s came in, I guess I need to find another diff. What about a lockright? The truck is a DD and it sees moderate trail use. 
Any of the auto lockers will do you well if the truck sees moderate trail use. I figure I'll throw this out there- I'll have a pair of 3.90 3rds for sale dirt cheap in about two months, located at Hill AFB in UT.
