for the tranny (t-45) i used royal purple synchromax and it took like 3.5 quarts so I just ordered 4 from mustangtuning.com well now americanmuscle.com
they have it on sale right now and if you use stangnet in the discount part at checkout it gives you an extra 5% off. they also had the deal for 10% off if you used the code americanmuscle but not sure if thats still going on.
for mine i bought 4 quarts of Mobil 1 ATF for the trans, i forget how much i needed, but that was more than enough.
for the rear diff i bought 3 bottles of Mobil 1 75w90 (IIRC) and a bottle of the sperm whale oil(Limited slip additive). and poured that in until it came out the fill plug. i have an aftermarket diff cover so mine probably takes a bit more.
Two months ago when I did my transmission flush and refill
I just bought four quarts of Royal Purple synchromax.Your T-45
transmission will only take 3.5 quarts though.
I would get Royal Purple synchromax if you have a T-45 transmission.
If you are changing your differential fluid also get Royal Purple gear
oil too. If your car has a 8.8" rear differential than it will take three
quarts but, get four quarts of gear oil just incase.
Prolly not what you want to hear, but I would suggest GM syncromesh fluid in that transmission and only suggest motorcraft synthetic 75w140 with ford friction modifier for an oem style limited slip differential.
Alan