s13 rear end knock on accel

[di-devol]

Hi, I recently started to build my rear end and now have a knocking sound when accelerating.

No sound on decel, coasting, braking, just decel. The more load I put, the louder the knock. I honestly can't tell where the sound is coming from.

Rear end:

Brand new voodoo13 ruca, toe, traction and solid subframe bushings(I did raise the subframe).
Brand new Gktech drop knuckles
Brand new axles, also tried used known good axles
Brand new calipers and pads
Brand new ichiba 5-lug hubs
Carrier bearing is good

No rubbing or scuffing on any of the parts(as they are new).

The e-brake cables are in their brackets and not rubbing the driveshaft.

The sway bar is not hitting the driveshaft.

I raised the car on jack-stands(securely), and had someone run through gears and still couldn't find anything.

lol the only thing left, is the diff, but i've never heard a diff make this kind of noise nor found anyone mention it. Replacing the diff is the last thing I can change and will do that tomorrow, but anyone have any ideas?