You should only use synchromesh and I really don't suggest anything else. It is kinda expensive also at like $8.00 per quart and you need 3 quarts total. I would get 4 quarts if you plan on dropping it out again sometime so you can top it off. If you really want to, you can use regular Dextron Mercon ATF fluid for cleaning purposes. Fill it with that, run the trans for as long as your batteries will take you, drain and refill with the right stuff.
