Click here to download installation instructions (PDF)
An oil catch can is essential on a performance vehicle to protect the engine from elevated levels of crankcase blow-by accumulated from high performance driving. Excess oil saturated air circulating back into the air intake stream can lead to degraded performance.
11-17 Mustang GT Catch Can Kit Details
Radium Engineering catch cans feature large 10AN ORB ports, a 4AN ORB drain port, 2-step oil separation baffling, and an O-ring sealed dipstick. These kits mount to the engine using factory holes on the valve covers and integrate perfectly with the surrounding components. These two oil catch cans (PCV side and Crankcase side) function completely independent of each other and are sold individually or together. They do NOT vent to atmosphere (VTA), thus are emissions and track legal. Closed loop systems remove the oil and sludge from the PCV gasses before it is routed to the engine to be burned. A closed loop system also promotes negative crankcase pressure for optimal performance. Furthermore, closed systems prevent unwanted oil vapors from entering the cabin. The dipsticks built into the catch cans allow easy inspection of accumulated fluid. No cutting, drilling or permanent modification to the vehicle is required.
The 20-0267-FL PCV Catch Can Kit is used for the Mustang GT in both the S197 and the S550 chassis. It mounts on the front right engine bank. 
This catch can runs inline with the PCV (positive crankcase ventilation) valve and retains it's factory function. When the intake manifold pressure is close to or greater than atmospheric pressure, the PCV "check" valve closes and, thus, this hose experiences no flow. Conversely, the PCV hose will experience "metered" vacuum when the engine is idling, steady state cruising, and decelerating. This would normally draw unwanted crankcase vapor, unspent fuel, and oil sludge into the intake manifold immediately after a high load run. Note: Because the Radium catch cans are pressure sealed, they are great for boosted applications as well so intake manifold connection is permitted. The kit installs in minutes and is easily removed for servicing.
The Crankcase Vent (CCV) Catch Can Kits (11-14 = 20-0279-FL, 15-17 = 20-0287-FL) mount on the front left engine bank of the Mustang GT, as shown below. This catch can runs inline with the crankcase breather port. At low loads it experiences atmospheric pressure, but when the engine is at high load (WOT), this hose will experience high flow out of the crankcase. This would normally lead to oil and sludge accumulation in the air filter intake pipe. If the engine is turbocharged or supercharged oil accumulation can occur in the intercooler which can lower the thermal efficiency properties of the heat exchanger and lead to decreased performance.
Sound tube has been removed in above picture for clarity.
NOTE: There are 2 different kits simply because of the variation in the vehicle's OEM intake design. 20-0279-FL is shown above and 20-0287-FL is shown below. 
Each kit includes the following:
-Anodized oil catch can with integrated condenser and dipstick
-Anodized laser cut Mustang GT specific mounting bracket
-Anodized aluminum -8AN adapter fittings and hose ends
-Enough 1/2" PCV hose for custom applications
-Stainless steel mounting hardware
For the ultimate in engine protection, Radium recommends the "Dual Catch Can Kit" which utilizes both the "CCV" and "PCV" catch can kits.
Dual Catch Can Kit Part Numbers:
11-14 Mustang GT (below): 20-0324-FL contains 1x PCV catch can kit 20-0267-FL and 1x crankcase catch can kit 20-0279-FL.
15-17 Mustang GT (below): 20-0325-FL contains 1x PCV catch can kit 20-0267-FL and 1x crankcase catch can kit 20-0287-FL.