I'm in the process of replacing the Delivery Valve seals and fuel lines on my S350D. I can't see replacing GP's without pulling the Intake. With everything installed, they're really hard to even see, let alone get at. It takes about 30 minutes to get the manifold off and then they're right there. You don't have to hold your mouth just right or anything. And you can clean all the coke out of the manifold. MB attached everything they could to that manifold, take a couple pictures so you know where it all goes.

Wayne