Drivetrain Passenger side rear axle play and clonk

Hello folks,

A quick video of my passenger side rear axle play, which is clonking when I turn to the left...I just put the car back on its feet after 2 years of modifications
I've not even driven 20 miles since I've started the engine for the first time this last Saturday.

Recap of all the parts I've installed for my 5 lugs conversion:
- New rear axles for a Ford Aerostar 89-97 (RockAuto USA STANDARD GEAR USA21181Y)
- North Race Car brackets
- New C-clips
- New clutch pack (RockAuto USA STANDARD GEAR USA16017)
- New cross pin and cross pin shaft bolt
- New axle bearings
- New rear brake calipers for a Ford Mustang Mach 1 03-04 (Summit PWR-S4824A)
- New rear discs from EBC Brakes

There is no end-play on the left side, might be a little too tight there.
I remember that the axles were too long so I had to grind off the ends to be able to put them in, maybe I did ground the right too much?
What do you think guys?

Forgot to mention that I've put Champion 75W140 LS oil in the differential

That's the fact: I can't find the info about this spec
I thought it was just replace the clutch plates in the same order and lubed and voilà...