That's the $64,000 question. Other than a lucky find of a good OEM pair of covers, most repops are made in China and the chrome job leaves much to be desired. In addition, the foreign covers have at least one bolt hole slightly out of alignment requiring a minor amount of filing to elongate the hole for proper fit. The surgery isn't visible when the cover is installed but you still know it's there. Lastly, the repop chrome covers come through without
oil baffles necessitating fabrication of baffles to keep the
oil from being sucked up into the PCV valve. How do I know all this? It's knowledge gleaned during the R&D phase for my adapter kits.
The last thing is that the repop covers don't always seal real well around the mounting bolt holes. This can be overcome by using a set of thick cork gaskets available from
DSC Motorsports and gluing them to the valve cover using Permatex Ultra High Tack gasket cement.