Thanks a million everyone it was what I was looking for from previous posts. I'll continue with what has worked for me - Valvoline 10W40, FL1-A and a 4oz bottle of zinc additive fro NPD and call it a summer.  GAGA, what do you mean by 20% Lucas? Is that how you add extra zinc phosphate? I've seen the name on the shelf but never checked it out. Thanks again, JEFF..................


64F100 57FAIRLANE500

I just changed the oil in my 319" Y. I was running Pennzoil 10/40 with 20% Lucas and a Purolator Pur-One filter. No problems with oil pressure.  
This time I used Mobil 1 15/50 which has zinc and a FL1-A. My engine has around 2500 miles on it.. My oil pressure is about 5 psi higher at hot idle now and I can feel the difference in engine freeness and power. Good Stuff!

"FREE SAMPLE"

It was probably me. At one time I owned a 1965 Austin Healy Sprite, A good fun car. It was a weekend and sometimes work because the fuel mileage was great. It alway had great oil pressure at least 20 at idle and 40 running. I changed the oil to Penz and when warm the idle was zero. I had no other explanation so I changed the oil back to Castrol all was normal.
A few years past and my sons friend/neighbor rebuild a Camaro and everything was fine after breakin and a few months of running. After an oil change the father came to me and asked what could be wrong with his sons engine as the oil pressure was not even registering on the gauge and it been perfectly fine. I asked what oil he used and he said Penz.. I said what happened to me and he drained it out. I don’t what he used but problem solved. Neither engine was hurt.
Just my experience, I won’t buy their oil any more.

56 Vic, B'Ville 200 MPH Club Member, So Cal.

YBLocks are solid lifter engines.  They require zinc or ZDDP additive to keep from wearing out the cams. Some people use conventional motor oil and purchase the additive separately.  I use Valvoline Racing oil in my YBlock.  It is made for flat tappet engines. My engine is not raced.  I use this motor oil because it's easy to find and it works.

Not too long ago in another thread there were several comments, if I'm remembering correctly, regarding Penzoil motor oil. I believe someone stated problems holding oil pressure? I usually try to use Valvoline but there is a good sale at a local store on Penzoil 10W40.  Any comments on Penzoil will be appreciated. I tried to find those posts but couldn't. Thanks, JEFF..............


64F100 57FAIRLANE500