Looking for ideas if anyone has one. I have a 402 that has a moderate valve clatter or knock on initial takeoff. It doesn't occur at idle and when crusing. I've noticed it after a moderately heavy foot just after take off when the oil pressure is the lowest. The pressure is good over all and the springs are good but I can't figure it out. I've heard that some big blocks had oiling issues to the cam, and Ive seen a kit installed which basically was a copper tube installed in the lifter galley drilled and tapped into the cam lube passage to increase the volume. I can't seem to find it now though and not sure that would fix it. Anyone know what I'm talking about? I can romp on it all day long with no troubles as long as it's not off idle. Help!