There is a BIG differance from reman to rebuilt. One is to replace worn moving parts. Rings,bearings,chains,gears etc. REMAN is to put it through a COMPLETE reman/remachine to same tolarance as new with mainly the block/head/crank after machining being reused. Rest of internals are new. I have uncrated REMAN gas engines from D. C. that were NOT remans but new with a reman tag applied. The engine pulled from your truck will go through a complete reman process once returned. It won't just get a bore job and pistons,new bearings and be good to go. Some REMANS outlast new because the BLOCK/HEADS are seasoned. They have already been through hot and cold cycles etc. In ANY machinery the term REMAN and REBUILT are TOTALY different and priced differant.