Allegedly my 2013 Z71 4x4 Tahoe has Rancho shocks and different springs in the ft. struts, but I can't find anything about replacement strut assemblies specific to the Z71. GM OEM lookup only shows individual parts. Depending on the source used, the shock for RPO 6TJ/7TJ is either 540624/20958798 or 540625/20958799. These are both the correct red color, so may be made by Rancho per OEM. But the only GM assy. I can find that supposedly is correct is AC Delco 903-600RS, which fits most 2013 Hoes. All other brands only have basically one option. No one mentions Z71. Rancho has the RS551784, which is for most. KYB has the SRM4079 Monomax which seems like it would be more appropriate for a Z71, but still isn't specific. Does anyone have any facts? I've spent the entire day researching without anything conclusive.