Originally Posted by
custom240sx
It is very simple...
The stock system is there for emissions. For performance, open breathers work better. If you want as much relief as possible you need to run as many exits for the air as possible hence the 4 ports being used on a valve cover.
I am just still up in the air in regards to the back of the block deal...is it really beneficial at all.
if you don't want to use the back of the block, its not a a big deal... but you will need to check the catch can on a regular basis so you can empty it so it does not overflow...