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I think he means compression readings, not the ratio.
I don't have a reference at hand, but if they all read within 5-10 pounds of each other in the 80-120 pounds per square inch range, you should be OK.
Start it cold and watch for smoky exhaust; black is gasoline, doesn't mean anything when cold, but gray/blue is oil, and could mean several things:
1.) Valve guides may be worn, allowing oil to leak down the valve shafts when cold. You'll get oil-fouled plugs fairly often.
2.) Valve seals my be worn (easy repair), same result as above.
3.) Rings may be worn or frozen into their grooves - unable to expand and scrape the cylinder walls free of oil. This may or may not require a teardown to fix. If you already own the car, start out with a dose of Marvel Mystery Oil, a great penetrant/lubricant. Squirt some into each cylinder through the plug hole, then let sit overnight. Add some to your engine oil and run at idle for 15-20 minutes. DON'T REV!
Change to fresh oil and filter. You should notice a definite improvement.
If the car blows smoke when warm and under accelleration, you have a problem.
Black (gas) smoke indicates too much gas getting into the engine when warm; check for properly tuned carburetors and that the choke releases completely when warm.
Blue (oil) smoke indicates one of the above problems.
WHITE (carbon) smoke, indicates that the engine hasn't been run at speed, and carbon has built up in the cylinders. Take her out on a good raod and slowly open her up, starting at about 40 mph accellerate up to 75-80 mph, then slow down and do it again.
After a couple of times of this, get her up to 40 mph and punch her, watching for smoke in your rearview mirror.
A lot of older cars that have been driven around in town for many years get a lot of carbon buildup. You can drive it out, or you can tear the engine down and scrape it out. There are also some additives on the market that you can put in your tank, or slowly pour through the carburetor. I've had good results from some of those, too.
Good luck!
Steve
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