It has been my experience with retro fitting pcv that the most important part has been to get the manifold feed as near to the base of the carb as possible. If you were to look at the PCV manifold port on a 250 for instance, the port appears to be in the center port of the manifold. However, in actuality, there is a tube that goes into the manifold directly under the carb.
If the PCV inlet is off center, it will lean the closest end cylinders more than the other end cylinders, requiring you to richen the idle to mask it. I've seen many bent 8s have a similar problem when the PCV was hooked up to the back of the carb rather than around to the front where it would enter at the primary throats.
