Great question. I have done a bunch of research on this. As we all know today's oils have much less zinc dialkyldithiophosphate (a.k.a. ZDDP) in them, which has been suspected to cause worn cam lobes in older engines. I have looked in to, and used additives such as GM's EOS, but was not real confident in their effectiveness. I have used Rotella T diesel oil, however this has also been reformulated for 2008 to meet new emission standards, lowering the ZDDP content to an ineffective level. So currently I am using Brad Penn oil http://www.bradpennracing.com/ This is made at the old Kendall refinery, remember the Kendall racing oils? This oil has elevated levels of ZDDP. I use 10-w30 but some guys I know with big blocks use 20-w50. Jim
After an engine overhaul in 2002, I've been using Mobil 1 15W-50 for the past 20,000 miles. No wear issues, or leaks. It still has the full load (1200 ppm) of ZDDP. Z. Ray
jim, i heard traco oil has the additives you desire. jim cowles recommends schaeffer semi syn oil. says it can lower engine running temps. so that's what i'll be using. ed
I'll be using the Kendal GT1 oil in my new 427 SO. Either a 10W30 or a 15W40. I have always used Kendal oil in my cars and have never had any problems. It also has one of the higher levels of zinc, too. I have heard that the synthetic oil can cause leaks. JMHO
RedLine synthetic, expensive as he|| and worth every penny. Started using it about 10 years ago. No leaks, no problems. Internal engine stays spotless with 5k changes.
Here is a very good article about oils. It is written for/by the Porsche guys, and these guys take their oils seriously... LOL http://www.lnengineering.com/oil.html Also, Brad Penn is partial Synthetic. Jim