why dont you run a setup like this.
take out the T fitting, put a regular elbow facing towards the firewall, then run another elbow off the rear fitting on the top of the valve cover. run both of those lines to a T then to one of the catch can's bungs on top. Then on the other bung run your normal vacuum line from the intake. Now for the part thats different. Make sure the catch can is the style that has a drain plug on the bottom like this one and run a line from there back down to the crank case like the OEM rear line just drains to.
That might solve the problem, if it fills up, it will just route back to the oil pan where it can get picked up again by the oil pickup and thus no blown motor.
Or am i just wrong?