I'm using dextron II in my 55 Imperial and it seems to be OK. The original trans fluid is no longer made or readily available in our area. RC Billings, Montanaaaaaaa --- "r.van.Lent" <remco.nancy@xxxxxxxxxx> wrote: > who realy know's what transmision fluid to use in my > 57 > I am told to use F type M type and dextron > I am towing a 6000 pound trailor > is that making any diverence > Remco > 1957 4 Dr Ht > daily driver > >