Cleaning up and doing oil mods on some covers I have when I noticed something interesting. These are both "later" covers with the 12 degree timing mark and the larger passages. Notice the oil passage at the top where the oil comes up from the pump and heads back into the block...the one has a square corner and the other is round like all the other covers I have ever seen. The square passage is a 75 cover...now why would they do that?? Its obviously cast like that so is intentional. Thoughts?
I think it has more to do with the foundry that cast the covers than Buick. I remember buying new cover from Classic Chevy in Mentor Ohio when they were still available that some covers had the words "die cast" molded in the cover. Maybe some covers were sand cast at some foundrys and others were die cast. I noticed in your pics, the unmachined inside of the cover with the rounded passage has a smoother finish inside the cover verses the other pic.
That is true. The small foundry markings are different on this one from all the rest. But a square corner? LOL
It does make you wonder about the foundrys quality control, or their casting techniques, and why Buick didnt inspect the covers more closely like they did for the Turbo cars in the 80's.
