Fluid Check on 440-T4

[SuperHbody]

Hey guys, need your help on this old beast. Been going over the fluids and wanted to check up on the 440-T4 transmission. Now the owners manual says to idle the car for 2 minutes or so, then run the car through all the gears before checking. Other sources tell me to drive the car highway speeds for awhile than check the fluid. Which is it? Thanks again!

[MattStrike]

It just needs to be up to temp and have gone through all 4 gears.

So both are correct.