I just got Precision Gear 4.88's installed at a local diff shop, and with the help of another lister installed the diffs in my 80 yesterday. I'm curious about break-in. I drove about 5 miles of slow streets, then stopped for a brew with 2 other members of the list. Then home. Then I did 10 miles, including a 1 mile segment of freeway. Today I did 20 miles of medium speed (40mph) with a few lights. Diffs feel warm, not hot after each run. The gears seem to run as quiet as stock, and I was listening hard. My problem is that I'm driving this truck to Cruise Moab (2500 mile high speed round trip) so I want to make sure the gears are broken in prior to the trip. I will be lucky to accumulate 500 miles prior to that, especially avoiding long freeway cruises. Any tips for making sure the diffs are well broken-in prior to my blast across Nevada and Utah? I do plan to change the lube just prior to leaving for Moab. I'm not super worried about this, but if 3 weeks of extra care will make a long term difference, I'm willing to do it. Thanks.