Easy there, jdpber.
I assume you're asking where we're plumbing them in. There's a rigid plastic pipe connected to a port at the rear of the driver's side valve cover, runs forward about 8" then makes a 90° curve to go to a port on the top center of the intake manifold. You'll have to pop off the beauty cover to see it.
The catch can goes inline in this circuit. So, in terms of flow, instead of going out of the valve cover and into the intake manifold, it goes out of the valve cover and into the catch can. Then, out of the catch can and into the intake manifold. How you connect the catch can to this pretty much doesn't matter as long as you have the flow correct. That plastic port on the intake manifold is very brittle and can easily crack off if you move it much at all. Safest method is to cut the plastic pipe where it makes that 90° turn a couple inches in each direction from the bend. So, you're basically removing that bend so you're left with two straight pieces of plastic pipe- one coming from the back of the valve cover and the other from that fitting on top of the intake manifold. Then, slip the hoses of your cartch can over those short lengths of pipe and secure them with hose clamps.
IMO, the best location for the can itself is on the side of the alternator, bolted to that accessory bracket. It's easy to reach for draining and doesn't interfere with anything else.
it's probably the screw on to the cap part. pretty much every adapter I've used seals badly. if it's a loner check that it's not missing a rubber seal inside. or just not the correct adapter. some bottomed out before they seal.
useful but annoying.