I plan on getting these 3 fluids changed shortly before I do a bunch of driving next month. What fluids go in these and what have you guys had best luck with? And where do you see these fluids for sale cheaper than most places???

I like Mobil 1. They have the gear oil for the diffs. I would just use a good synthetic transmission fluid.

i used mobile1 for rear dif oil and i used the mobile 1 full synthetic dex3 because all the dex6 i found was partial synthetic. the front dif called for conventional so i put in lucas heavy duty gear oil. you can convert the front to run synthetic if you swap out the black vent thing for a white one from gm

so you have to change the front axle vent if you put sythetic in it? what would happen if you didnt change the vent? (i put synthetic in my front diff in like may and didnt change the vent, havent really used 4wd yet tho)

I use Mobil 1 75w-90 synthetic gear oil in the rear diff and 80w-90 conventional in the front diff. I use AutoTrak II fluid for the Autotrak transfer case. I carry everything you need to do the maintenance if needed, just let me know.