T. Fluid is 3qrts for manual. I know if your filling using the 1qrt bottles of Redline with the manual push/pull tube, a lot of fluid will still be in the bottles and tubes when you change them. I'd get 4qrts of the 1qrt bottles rather than 3. You'll be missing about a quarter of a bottle. (2.75 qrts) Or better yet, buy Redlines 1 gallon container $71 on Amazon) and fill until it dribbles out of the filler hole. (just as the writeup shows in the Tech section of this website) All the Best!
*- I'll need to do this myself next week after about 50k miles and 18yrs ago last time I did it. My reverse isn't going in gear so I know the fluid is low.