You guys with the older motors really ought to be using a higher viscosity synthetic, the film strength is multiples of dino oil, and it doesn't shear down nearly as quickly.

And for peace of mind add a bottle of Ford or GM "Engine Assembly Oil", which has a high enough zinc content to more than offset the new EPA regs' recent reduction in zinc in motor oils.

The old wives' tale about switching to synthetic in a motor that is used to dino oil causing all sorts of oil leaks isn't something I particularly buy into. Yes, it may remove crud that was plugging areas around a bad seal, thus allowing a leak, but that meant the seal really needed to be replaced anyway. So what's the difference. Much better protection for the motor.