[Alex V.]

For a while I was very anal about keeping extra ZDDP in my '85's 454, but I've slacked off based on reading and more observation. My dad's '86 K20 (350) has 361,000 miles on the original cam (two valve jobs over the years - that engine's been used for a lot of pulling) and never had a drop of anything except conventional oil (10w30, 10w40, and maybe some 20w50) put in it. My 454 has 122,000 on it - I've had it since 77K and have used Schaeffer's syn blend for most of that time. For a stock engine that's maintained well, my opinion is the only time a ZDDP additive or high-zinc oil is necessary is during break-in. And don't fall for the "synthetics leak" nay-sayers - Valvoline Maxlife is good stuff that a lot of people trust.