Wow I am moving my questions here because ClassicOldsmobile cannot simply answer a question, they must tell you how much more they know about my car and engine build than i do. I am all for advice, but poking holes in every process I do is tiresome. I have built two W-31 350's and a W-30 455 before and to my knowledge they are still running strong and without hiccups. So the fact that I am retrofitting a 1968 into a 1980 car seems to unhinge them a little. Maybe it is retrofit and the 12 year gap. It all comes down to $$$ for me. There is the "old", fix what's broken, anticipate problems, and the new way, leave nothing old if there is something new that can replace it. What a waste of money! I got the engine cheap and its a good one. Because I am doing most of the building, not paying $100 an hour to have it done, I am going to have a "new" engine for about $3000. Check out the price of stock to HP crate engines. I have the time just no money to waste, so what better way to do your last ever project? I still like to read the cautions, because they have changed my parts purchases, but I also know there is more than one way to build Dr. Olds engines, but probably only one right way! The question now is CR and I have a pretty good idea. The 9:1 pistons are NLA so it is either 8:1 or 10.25:1. Since I want a bit of pep in mine, 8:1 is out of the question. The 10.25:1 pistons are still dished and are cast as ALL Olds pistons. Forged according to the Machinist are heavier and harder to balance, not to mention about double the cost. All of the equation for the CR is stock/same except bore size which I do not yet know until the machinist does his magic. At worst it is 10.25:1 but it could be lower and to my mind, that is better. Without vvt and a computer, O2 sensors and Cat Con. I will only have on way to retard the spark, the distributor, and the advance curve. We have pretty good gas in WA, I could get double thickness gaskets to lower the CR slightly...but there are not many other ways to lower compression by a single point other than pistons. My original build was going to be 9:1 as I have built two that way and they were perfect! What say you?