LSD fluid flush

I have a bone stock 92 240 w/hicas. I need to do an LSD flush asap and possibly a tranny flush, too. what’s your recommendations for fluid? what would work well (and last me for awhile)?

Any thick Gl4/Gl5 compatible gear oil is good.

IIRC, GL4 is spec’d for the VLSD and GL5 is not the same as GL4.