Ford 8.8 rear end problem?

In my crown vic I picked up a used ring gear and pinion and both were in good shape so I swapped in them in place of my stock gears I used the same bearings and factory shims just a gear swap no overhaul since it wasn't needed now I got it all together and there's a noise coming from the rearend its not exactly a whine but the only thing i'm unsure of was setting the pinion. Would that cause a noise?

Never use a used ring and pinion set in another axle. The wear pattern has already been established, and trying to reinstall them in another axle will just result in a noisy rear end. Also we're talking about tolerances in the 100ths of an inch here, so there's no way you can just eyeball it and expect everything to work without issue.

Yes, could be excessive backlash, "drive" or "coast" pattern to deep or too shallow on the ring gear face (directly related to pinion depth). If gears were easy, it wouldn't scare the Bejeezus outta most shade-tree mechanics… Swapping gears and tearing down an automatic trans are a black art to most people.