[Half-Inch Stud]

Originally Posted by Will

The reason there are only 8 is because a stem seal on the exhaust side isn't as important as on the intake side. Positive pressure in the exhaust port helps prevent as much oil from going into the port as compared to vacuum on the intake side, and also if a little oil does get down the valve it's no big deal as it's not being sucked into the cylinder, it just gets blown out the exhaust.

This upgrade alone "Modernized" the PMD V8 design to todays best practices....minus all the Bureacacy.