Say What?: Is purring a sign our new piggies are settling in ?

[MasterBlaster]

Greetings Friends,
It's been twenty odd years since I had my last guinea pig and now I have rescued two young brother boars. Yesterday after a couple of hours floortime my partner and I picked up our two new family members and gave them a good cuddle and gentle scratch for fifteen minutes. Both of the piggies started purring and I wondered if this means our new piggies are settling into our home okay. As we only got them earlier this week and they are presently in okay, but not great temporary accomodation (in process of building something more appropriate and spacious) and I thought they may be a little stressed with having left the rest of their family and taken up in a strange environment ?

Thanks in Advance Master Blaster