[Jeff H]

But you're still comparing an LS6 with docs(buildsheet) to a COPO with no docs and you can't make that comparison. I would take the LS6 with docs over a non documented COPO without the original motor. If the COPO had the matching #'s motor, then that's as good as documentation and I would take the COPO over the LS6. We all know engines get restamped, but someone can forge a buildsheet as well. Buildsheets are known to be found in the wrong car so a buildsheet isn't bulletproof evidence either.