Full Synthetic Gear Oil 75W-90 GL-5

I need 8 quarts of Full Synthetic Gear Oil 75W-90 GL-5 for the differencial in my Safari Trek motorhome. What brands offer this gear oil spec and where are they normally available online? Thanks. Gord & Linda w/ "Camper" the Cat Coaldale, AB (May-Oct) & Mission, TX (Nov-Apr) Travelling Coach: 2005 Safari Trek 28RB2, Workhorse W20 Chassis, 8.1L V8, Allison 1000 5 spd AT Car Hauler: 2014 JIMGLO Ego Custom 17'+ Aluminum Tilt-Bed for Abarth or Corvair + Mobility Scooter. Daily Driver/"Toad": 2014 Fiat 500c Abarth Cabrio Turbo 1.4L I4, 160hp, 5 spd MT Vintage Car 2B: 1965/66 Corvair Corsa Convertible, Air Cooled 164cid Boxer 6, 4 x 1bbl carbs, 140hp, 4 spd MT Stationary Coach: (Mission, TX) 2008 HitchHiker 34.5 UKSBG, 36' 5th wheel w/ 3 Slides
Central Washington
Amsoil Severe Gear is great stuff, but if you want something off the shelf, Valvoline Synpower 75W90 meets the SAE J2360 specification which is a tougher specification than just GL-5.
West Michigan
Originally Posted By: LotI
Off the shelf, Mobil 1 75w-90 is available. If there's an AAP near you use an online coupon to get it for $7.69/qt Online, Red Line and Amsoil
What code?