I know I read the answer to this here someplace.  I am starting the build of my DPMS 308 stripped lower.  I understand most of the parts interchange with the AR 15 and I have assembled an AR lower before.  Questions:  Is there any reason to prefer one LPK over another.  It looks like RRA has them in stock and DPMS does not.  
Also, remind me how the 308 build differs.  I recall that there are 1 or 2 differences.  But I can't find the posts on this board.

Thanks.

.308 uses a set screw instead of a split pin for the bolt catch.  .308 spring & detent for the rear takedown pin go in a hole under the hand grip instead of going in from the rear where the buttstock attaches.  .308 has a trigger guard machined into the lower already.  All of this is specific to the DPMS .308 lowers....not sure about other brands.

And DPMS uses larger take down & pivot pins & they do have a larger bolt catch ,but the std. AR should work. Also a diff. buffer spring & buffer ,when you get that far on your lower.

thanks for the info.