<VV> LM Engine Questions

[Rodney Sampson]

All:

   A few engine questions  (65 140Hp)

1)  Did a cylinder pressure study...
      1-150 3-175 5-180 2-150 4-160 6-150
      At what point should I consider rings ?

2) At present, I consume 1 qt of 20w50 oil per 40 mi run to and from work...
     excessive blowby and plugs 3 and 5 get fouled atleast once a week.
     With the above readings , I am assuming bad guides, anyother 
possibilities ?

3)  Lifters, I'm considering replacing them all but the blurb from 
Clarks advises
      against replacement on an old cam. I've got a couple that are very 
sensitive to
      oil levels/pressure...Comments ?

Thanks
Rodney