Hey guys im thinking about doing a trans flush but had a couple questions. First is it safe?i've got a 97 4.6 it has 159,000 and im not sure if it has ever had a fluid change or not. Its been kind of shifting funny the past couple weeks so i figured ill take it down to the shop. And I've gotten a couple people telling me that i should replace on of the quarts with trannsx. Anybody got any opions? Would like to here them.