The bearings aren't new. It looks like the engine was rebuilt before I got it as the bearings were all in good condition. I believe they are the babbitt type bearings, except the front main cap has an insert type.
When I test fitted them I did have all of the other main bearings in, but not torqued down. Also, the plastigauge came out looking the same as when I put it in, there was no difference in width.
