You are right about being concerned about the slits in the 1954 (1955-1st?) and earlier valve covers.
Regarding:
Someday I would love to see statistics on how GM can say that all of the oil is being filtered and not just that oil that is closest to the sump.
What does that mean?
What engine?
What oil.
What filtration system?
- Are you referring to an engine that uses non-detergent oil.
There would be a problem, This is probably what you mean? However, this system does filter all oil, eventually, but will not get the sludge out.
- Are you referring to an engine using detergent oil?
There would be no more of a problem than in your system
- Are you criticizing the pump used in the GM by-pass (or full-flow) systems.
If so, your system has the same problem/feature?
- Are you afraid that your system (or, any system) only filters oil closest to the pump?
Do you think that the oil in the pan is not well-circulated in the pan (sloshed around), when you drive, turn, stop? Maybe so, if non-detergent oil is being used (no matter what pump and what filtration system is used).
