Noise when releasing clutch

I need some ideas as to what this noise is that I've had since I swapped the transmission. It's a tapping noise when releasing the clutch pedal. It is most noticeable/loud after you've come out of gear and into neutral. I really had no idea what it could be, and haven't had a helping hand to get under and listen around while I recreate the noise to try and see where it's coming front.

https://youtu.be/6woVcKFxL0c

Noise when releasing clutch