What is nice about rubbing elbows with guys like some of you who know how to really put an engine together is that shadetree guys like me can learn a lot. I'm probably like most car guys, I just take the parts out of the box and assume they are within specs.........you guys check every piece and make corrections and allowances to make them fit properly. I think that is what happened with this engine, the end gaps were too tight and butted up and caused the rings to fail.
As far as maybe overboring the engine another 20 thousandths, it looks like the scoring might be deeper than that in some spots, but won't know until a machinist looks at the block. If boring it over is possible that would be great, and save us having to use a new block. But it will probably be smart to buy the block we found locally anyway as Olds 455 blocks don't come available very often around here.
Thanks for all the help, we will post what we find when the engine comes apart.
Don