8 3/4 Issues

I purchased a complete sure grip 3rd member, 741 case, it had a set of 3.23s in it so I decided to take it apart and put 3.55s in it instead, this was my first time ever doing anything with a rear-end so it took me some time, once it was reassembled the lash was somewhat questionable but I decided to put it in and try it, long story short, its in the car now and the rear end whine is terrible, pretty sure my lash is off and that's what causing the noise but just want to get some other opinions before I decide to take it all apart again.
Thanks!