I would send it off to ECGS. Almost nobody rebuilds diffs correctly and when they aren't set up perfectly, they will make noise and their lifespan will be way shorter than from the factory. From what I've heard, ECGS does it right.
I won't argue with this. ECGS does awesome work and has a great reputation in the industry.
I did partner with ECGS to create a couple of helpful DIY videos. The first one is a rebuild/re-gear of our front diff with an Eaton E-Locker Install. What that video doesn't go into great detail on, our 8" Rear Diff video covers.
You could use our videos to knock out the pinion bearing swap yourself. Since you're only swapping out the pinion bearings, you can keep the same shims and your backlash won't change. You could go with another crush spacer to set the pinion bearing preload, but a better option would be to buy an ECGS solid spacer and dial in the preload with the shims provided.
But, if doing the work doesn't sound all that great to you, getting a diff from ECGS is a great way to go. This is also the time to re-gear if it's something you've been considering. One of the coolest things about using ECGS is you can severely limit your downtime. They have diff cores ready to be rebuilt to your liking. You make your order, they send them to you, you pull yours and send them back to satisfy the core charge. Easy Peasy. You rig will only be down for as long as it takes you to swap the diffs. You don't have to ship yours off and wait for weeks to get them back.
I can post links to my diff replacement videos for anyone that would like to watch them. Let me know and I'll reply back with the links.
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