you can run a catch can in either of two ways
- as a vented catch can with filter on top (nothing enters the throttles)
- as a sealed catch can (the oil gets trapped in the catch can before the rest of the air travels on through to the throttles)
which is best is really up to personal preference and the condition of the motor itself. with venting it you can sometimes get a small wiff of oily smell when idling or if you have been thrashing it. not really that noticable though.
i run mine vented with a filter cuase i really don't want any of that shit getting into the throttles.
there are different opinions out there on this topic but at the end of the day it comes down to the condition of the engine and how much thrashing you do.
well and of course it does look nice too.
this is how i run mine and it seems to work very well. most people run it this way also.
block off the connection going into the manifold (or else you'll ahve idle issues) and run both of the camcase breather lines to the catch can. job done easy.