Chevrolet Repair: Seals, intake manifold gasket, valve seals

Question
I did a compression test and all cylinders were good 3 at 150 4 at 160 and 1 at 170 wet test no difference in your  opinion do you think it is a good chance bad o rings are oiled plugs and exahust smoke ? Thankyou
-------------------------------------------
The text above is a follow-up to ...

-----Question-----
Hi, I want to change the valve stem O Rings on a 350 ,i looked on line for the parts which i found Fel-Pro-Part SS5112 INT- EXH-o ring and Fel Pro Part SS10058 OPT- Umbrella Seal For use W/O Ring Seal , My question is what is the differnce between the two and which do you suggest to use . Thankyou.
-----Answer-----
Hi Garry, One is just a 0ring type and the other is a umbrella. The umbrella type is a better seal then the 0ring. I would use the umbrella seals.

Hope this helps

Have a Great Day          Mark

Answer
Garry, There is no way to check the oil rings by doing a compression test. Many people think by doing a compression test or leak down test that you can check for bad oil rings. This is not true! Think of the oil ring as a windshield wiper, it just wipes oil off the cylinder walls and doesn't have any part of compression. Now this being said you have a oil burning problem right. If your coating spark plugs the problem is most likely to be the oil rings or bad intake manifold gasket,(letting oil through from the lifter galley). Valve seals really don't control that much oil flow, unless the valve guides are wiped out or the drain holes in the top of the cylinder heads are plugged up...

Hope this info helps

Have a Great Day          Mark