VLSD min oil requirement

[dedoom]

Hello everyone! Being a base owner with blown diff bushings and wanting to not one wheel peel anymore, I recently purchased a vlsd off a g37 owner and installed it with whiteline bushings this past weekend. My concern is that when I swapped out the old fluid for new Mobil 75w-90, I completely emptied out the diff by tilting it and then I added the 2 quarts. I then later read a thread this morning where the actual capacity of the diff is 2.25 quarts. Am I screwed? I'm only asking because I feel some tension when in lower speeds and in reverse. Maybe it's because I'm not used to two wheels spinning and bushings that keep the diff in place? Lol Also, if I need more fluid can I just top it off with the same oil or should I just change it up with redline? Thanks in advance