Most tranny fluids for a specific trans type (Dextron/Mercon etc.) will work just fine for most applications. For instance, I run a modified C-6 trans (1968) if I were using original internal soft parts I would have to use Type F fluid because of the materials used back then on the bands and clutches. However, I have all TCI internals with modern materials so I can use modern fluids such as Mercon, B&M, Redline and others which have better qualities than the original Type F fluid. So the question you have to ask yourself is what was reccommended by the manufactorer when your tranny was stock? What modifications have you done to it as far as bands and clutches? All the modern fluids are good and in most cases exceed the factory criteria. Just make sure that what ever you use will not have adverse affects on the materials in your tranny. I've heard of Chevy guys using Ford fluid because it make their trannys shift harder. But Dextron in a Ford tranny will make it shift sluggish. There's more to it than just name brands as each fluid is got their own chemical composition and additives. I took a college course on lubricants about 10 years ago but I'm sure there's new stuff out there since then. George