Also: <quote; Here is my 2cents. I have read a lot about this from this site and a bunch of others. My final was to use CASTROL 20W-50 Syntec. It says right on the back of the bottle of oil "Recommended For Classic Cars". There web site says this is the only oil in there line that conforms to 60"s cars with flat tappet cams. That was enough for me. What do you think? >
I just got off the phone with Castrol. They claim a min. of 1200 ppm zinc... for the 20W50 and that is the only oil thay make that they will tell you what the zinc content is. All the rest of there oils are API Sm compliant. which means 800 ppm zinc and phos. or less.
In my opinion 1200 PPM is going to be the absolute minimum to keep moderate to stock cams alive... If you run a rowdy cam add a supplement like the STP red Bottle for zinc fortification if you are Loyal to the Castrol.
I looked at the data sheet... The data sheet does not list any of the ingredients in the oil. just sheer points and vapor temps... Kinda weird.. But the person on the phone keep telling me when I asked about amounts or maximums that all that info was proprietary and not for public knowledge. >
I personally prefer Castrol 10W40 (dino) with STP red bottle to help boost the zinc %. I also have been reading good things about the Brad Penn oil, so I may give it a try.
I use the full syn Mobil 1 in my Beemer and Blazer and have noticed they do run better on full syn. There is controversy in the Beemer groups about full syn in the early oil heads ('94-'00). But both of the mills were designed with lower ZDDP in mind, so I don't have any worries.
