fluid change

[amccomb]

I just recently bought a 66 k10, The guy I bought it from said it had been sitting for 4 yrs. So I am going to change the diff fluids and the tranny, transfer case. I am new to these old trucks, and to any project trucks for that matter. My plan is to take the covers off the diff's to get a look inside and see whats going on they both leak anyway. Whats the best gear oil to use? Can I use the same gear oil in the tranny as the diff's and transfer case. I guess I have a lot of ? so any info is good. Thanks in Advance!