which is better for plumbing the oil catch tank
breather pipe on side of rocker cover
or
from the pcv on tip
or should i just plumb both into the catch tank
Just so you know the PCV is actually situated under the inlet manifold. (small T-piece)
The PCV and rocker cover are both linked via a Y-piece as standard anyway. Just remove the mushroom valve on the TIP and the pipe its connected to that runs back to the hardline (where it splits into the rocker cover). At the PCV end of the hardline remove the PCV valve itself under the inlet manifold and sleeve the pipe where the PCV originally was with a new piece of hose approx 2-3 inches long. Now that you have removed the PCV you need to blank off the vac hose that ran off it up to the bottom of the inlet manifold.
Now run a hose from the Y-piece on the hardline to the catch tank. Then run a hose from the outlet of the catchtank either to atmosphere or back to where the mushroom valve was originally fitted in the TIP. Most people tend to vent back to atmosphere otherwise your likely to get oil residue back into the intake which pretty much defeats the idea of fitting a catch tank anyway. Remember to blank off the TIP if you do decide to vent to atmosphere.