All fluids due to change on 90 3.0 3VZE with 200k miles. Thinking on Synthetics and curious to recomendations on brand or weight. Have 4WD/MT. I know it will be expensive, but would like to go synthetic on both diffs, M/T, Transfer, which is about 10 quarts. Best I can decipher all areas require 75w-90 except rear diff which recommends 80w - 90W or straight 80W. Not sure why such a small difference. No off roading with this vehicle, street use only. I think the only widely available synthetic here is Mobile 1, small amount Amsoil and some Redline. Any recommendations and advice, warnings, help appreciated. No known problems with vehicle as is.