Nvm. It uses ar10 a parts for lower, barrel nut.
Yes, you can use an LR308 pattern barrel and BCG in an AR-10 pattern upper receiver with the AR-10 pattern barrel nut.
Yup had to dig through some really old threads but found it. These sets are almost as cheap as 5.56 sets. Ordering one tomorrow to start getting one together. Not going for anything super fancy but better than a stock one in same $ range. Don’t want to have more than 1k into it minus optics.