compression test question

re: Lull 225 Slant 6

re: PCV. This Lull engine does have a PCV system. PCV valve rattles and breather and lines are clean.

re: "cruddy mess." When I bought this machine, I had the carburetor rebuilt, and replaced the fuel pump, and the oil isn't watered down with gas when I change it; so in the time I've owned it, gas isn't leaking into the crankcase. I bought it in 2000 so by that time it was already 25 years old; the hour meter read 5000+ but wasn't working. Other than the carb and fuel pump replacement, tune ups, and oil and filter changes, I've done nothing with the engine (until this recent valve stem seal replacement). I didn't know its maintenance history, but looking at it when I bought it, it definitely was not maintained as well as it should have been.

re: "As above, WOT smoke is usually weak, shot, or broken rings. Probably not borken as yo are getting reasonable compression on all cylinders. BTW, I would not get carried away over the 145 psi; the older factory manuals say 110-140 psi as a range limit for the /6's. It could be excess oil or a valve adjustment that is causing the 145 psi reading. Oil in the cylinders can make readings look good."

This is where I'm a little confused. The vibe I'm getting from AJ/FormS is that 145 psi, the highest compression reading I have, would be the benchmark for the entire engine, and numbers less than that in the other cylinders should be filed under "compression loss" (?) (And what about the +/- 25psi rule for general engine health?) And besides this forum, I've read that 125psi is an acceptable number for a stock 225. If "oil in the cylinders is making the compression look good," what would be the source of the oil when I do the compression test, if that indeed is my case? (up from the pan thru worn rings or down from the top thru worn valve guides?) (I'm not squirting oil into the cylinders when I do the compression test.) And what I'm getting from nm9stheham is, piston rings can be "weak or shot" and still give good compression numbers (?)

This engine always starts right up, and besides the smoking at high rpm, it purrs like a kitten and runs like a top. It refuses to die. The reason I ask all of this is, if I knew that the smoking would cease with a valve job, I would have that done, because accessing that part of the engine is super easy. Removing the entire engine for a ring job would be one big pain-in-the-***, because all of the hydraulics would have to be removed. And if I was going to do that, I would simply get another engine (I see a 22,000 mile Valiant engine on C/L for $700.)

Maybe all of this is "Tired Engine 101," but it's not all that clear to me. I'll do another compression test to see if the numbers have changed since I've changed the stem seals and adjusted the valves. Thank you for the feedback.