"Catch Cans" are used to allow the crankcase to breathe.  The natural operation of the engine creates a positive pressure within the crankcase by some amount of combustion gas/air to seep beyond the rings.  There is also a natural force acting against the piston rings as they travel up and down the cylinder bore.  During this time, you want to remove as much pressure as possible from the bottom of the rings.
Allowing the crankcase to breathe has many positive advantages which most PCV systems are not designed to handle from a performance aspect (especially once you add forced induction:

• Decrease in blow-by
• increased ring seal
• less opposing pumping forces under the pistons
• opportunity to run low tension rings for increased power output
• lesser opportunity for crankcase pressure to create oil leaks such as oil pan, front and rear main seal

  EXAMPLE:
Lets be a little exaggerated so you get the idea.  Inflate really anything to its maximum inflation.  Hard to push it right?  Remove half the air from it.  Easier to push down right?  Now do this over and over 4000 times a minute at the same stroke distance and see which one wears you out the quickest LOL. This is an exaggerated example but it gives you an idea of whats happening in the crankcase. 

Stock PCV systems simply are not designed to remove the pressures in the crankcase once you increase the performance and cylinder pressures of a modified engine.  

850Fab is here to offer engineered solutions for crankcase ventilation.  We will have many variations and will be continually updating with new designs.  For now, I will be taking orders for 6(L) x 4.5(W) x 5(H) Catch cans or any size within 1" of any dimension at the listed price in any configuration you would like including two mounting bungs.  You can put the AN bungs on the side, front, back, or top with no upcharge.  All tanks come standard as internally baffled.  The baffling wall on the inside allows the crankcase gas to separate the oil and water and only allow the vapor to exit the atmospheric breather filter.  I do not set them up with drains.  I prefer to use a vacuum pump to suck the oil out.  There is no mess involved and no valves that can leak.  IF you do still want a drain, I CAN add one.  If your setup requires a recirculated breather back into the induction system, please let me know.  Once you place your order, please contact me via EMAIL at [email protected] so we can discuss your configuration.  My goal is a 1 week turn around!