Blackstone Labs is one that I see referenced quite often and where I've had the oil from the 6.2L in my F-250 analyzed at about 20K miles. The standard analysis runs $30 and they will send you a free collection kit that includes a pre-paid mailer to send your sample in via USPS.
Blackstone Labs Web Site
TT: 2019 ORV Timber Ridge 23DBS, Blue Ox SwayPro 15K/1500
TV: 2019 Ford F-250 XLT SuperCab LB, 6.2L, 4.30/e-locker, 4x4, 164" WB, 3216 payload
TV: 2014 RAM 1500 Big Horn CC (Traded in)
TT: 2015 Jay Flight SLX 195RB Baja Edition, Andersen No-Sway (Traded in)