Check this out. This came from Performance Jet. I too am running a mild built 468, it sure got my attention....
Originally Posted by JEThro
Engine oil alert 2010
There is something going on in the automotive oil industry today that will effect all hot rodders , hot boaters and high performance engine enthusiasts. Performance Jet would like to bring this issue to your attention in the hope that you can avoid the costs of pre mature cam shaft failure on your jet boat engine.
With today's engine oils we are seeing the reduction or complete elimination of Extreme Pressure oil additive packages (EP). This EP package is known as ZDDP or zinc dialkylidthiophospate. Basically this is a mix of Zinc and Phosphate. ZDDP has been an important additive to engine oils for over 70 years. It has an excellent track record at protecting the sliding metal to metal cam interface on your high performance engine.
Why is this EP package being removed from engine oils? As part of an effort to reduce vehicle emissions the U.S. EPA offers vehicle manufacturers "credits " for early implementation , as well as penalties for violations of emission standards.
By this year the EPA has called for the life of catalytic converters to reach 150,000 miles. The rub here is that the EP package of ZDDP is poison for catalytic converters so the manufacturers have pushed for the elimination of Zinc and Phosphorus from all motor oils. In the last ten years all motors are built with roller tappet cam shafts so this change does not effect the new generation of engine owners. Unfortunately, the folks with high performance flat tappet cam engines are left out in the cold. Without the EP package you run the risk of premature cam and lifter failure at break in or on normal high performance use.
In the past, ZDDP has been added to oils in amounts resulting in approximately 0.15% Phosphorus and 0.18% Zinc. The film of the Zinc and Phosphorus compounds provides a sacrificial wear surface protecting the base metal of the cam and lifter from wear. According to the S.A.E. tech bulletin #770087, operation of a flat tappet engine without adequate EP additives quickly leads to lifter foot scuffing and cam lobe wear.