First Gen 2002 trans fluid amount

After swapping the radiator, my trans fluid seemed to be off by a little. I checked it when hot and the stick was reading lower than it should after driving for 60 miles. (below the first hot notch) I added some and checked when cold as i was told i should do. it was reading at almost the same level as it was hot. So now i’m thinking i should just drain and refill it to know what exactly is in there. any advice here? How much should I put in after a drain? it’s the 4.7 2WD

 

3.5 to 4 quarts

atf is checked with the fluid warm and the engine running.

 

And it's never a bad idea to do a drain/refill especially if you don't know the last time it was done.