95 Astro AWD Transfer Case Question

Hi everyone, this is my first post here. I love all the knowledge and great advice on this forum! I bought a 1995 Astro AWD EXT from a co-worker for $400.00. I tore out the rear seats, put in a rubber floor, a cargo bulkhead and I use it to haul around band equipment and tools for my side plumbing projects. After a few trips to junk yards and reading this forum I have this thing on the road and I absolutely love it! I think I have determined it has an open 342 rear end. What fluids should I use in the transfer case and differentials? I have read on here about the new GM synthetic in the newer ones but will this work in the older Astros? By changing the transfer case fluid will that also help transfer the power more evenly to the front and rear axles?

Welcome to the forum!

The differentials use SAE 85w90 fluid, synthetic not necessary. Not sure on the interchangability of the synthetic fluid for the transfer case, best to check with the dealer. Transmission fluid and filter change every 36,000 miles will help the trans last. Don't know if you're familiar with AWD, but all 4 tires MUST be the same size, same brand is even better.