Hi once more. We've kind of gotten away from my last question. I don't know what type of ATF is currently in my 69 727 trans. I need to drop the pan to replace a leaking pan gasket. Can different types of fluids be mixed? Or do I need to drain the entire transmission system so I know whats in it for sure. I was planning on using Dexron ATF because that is what the owners manual calls for in 1969. Thanks for the advice.