tapping/knocking sound

[DerekTheGreat]

Oh. Well, you can still source a 14 bolt SF from a light duty C2500, but you'll now have six lug wheels in the back and five lug up front. I'd just put another ten bolt in it if it was my truck. Source it from a 2WD Suburban and you'll get bigger and better brakes. Rear end might be dead from putting up with the fat Suburban for all those years though.

 

[rio21]

Update:
Found a junkyard rear end to swap in, noise is gone. Thanks everyone!