[f5fstop]

Your owner's manual probably recommends Dexron III, but the new Dexron VI, is the best and can be used to replace Dexron III. As for a filter, I never recommend just changing a filter, since 25-40 percent of the fluid remains in the trans and torque converter (depends on the size of the converter). I recommend a total trans back flush, but only with the Kent Moore machine that GM and other manufacturers use. I do not recommend the local oil change shop that uses a cheap back flush machine that is worthless.
Doesn't actually cost much more, but it will flush out all the old fluid, in the trans and the converter, and flush out contaminants, and fill with fresh fluid.
I had it done on my Vette, and it was $109.00; whereas a fluid change and filter was $70.00+.