If I'm not mistaken the original fluid callwd for in my 98 gp gt was dex iii. The "official" replacement is dex vi. But there's a good deal of type-iii(h) floating around, which replaces dex-iii(h) or (g) or dex ii even, the predecessor to dex iii. And I've heard that dex vi isn't the best replacement for iii, despite being the approved replacement.
Will I get into trouble with type.iii(h)? Can't see why.