Questions about Rear end fluid?

[2ez 2spd]

I want to change mine and I think the suggested fluid is Dextron LS is this correct? and if so can I get it anywhere? or is there is something better to use, thanks

[1TZSLO]

I went to RK chevy and it was 33bucks per bottle. 75w90

[Peter Pan]

I have been using RP in my boosted C5 for 5 years now and like the results, also in the MN6http://i29.photobucket.com/albums/c293/elsloan22/emotions/eagle.gif