ATF for 02 Allison

I have an 2002 Silverado2500HD with the 8.1/Allison Combo. I need to change the tranny fluid. I have read that for that year you can not use Dexron VI, only Dexron III or Transynd. I don't want to spend the money on the Transynd, so which fluid do you recommend that is Dexron III only? Any help would be greatly appreciated.

You can use Dextron VI in the Allison.My father did call the dealer on this once and said Dextron can be used.There is special ATF for the Allison and it is not cheap by the gallon,about $22.00 a gallon.

I read that the Dexron VI could not be used prior of 05 for the Allison's. Is this correct?

That is not true and call the dealer on this.