There is a pattern yes, but as nothing conclusive can be gained from it, its pointless. it could be any of the following:
*Oil seepage in 1/3 causing a better seal and higher compression.
*Extra coking from burnt oil in 1/3 causing higher compression.
*Mismatched heads.
There is otherwise no indication of a dead cylinder. No deflection on the vacuum gauge, no unevenness when it's running and no obvious lack of power.
All this is very well trodden ground for me, albeit with different motors. Everything considered I might do a wet compression test. I don't have access to a leakdown tester or all the necessary parts to make one currently.
Could you please explain this?Have you done a head check for CO content in the cooling system?