Since in my searches I noticed a lot of indefinite information on how to install a catch can on a GXP (LS3) I thought I would document my install. Very simple overall, took about 30 minutes.
Wrenches/Socket (to install bracketry)
Here is a picture of the front of the LS3 with no modification aside from an intake. I will be using the bracket next to the fuse box to mount the can.
First step: Remove the intake breather line from its location above the valve cover, and move it out of the way.
Now remove the plastic line from the plastic box (insert function/part name here) with needle nose pliers, move the line aside,remove the wiring connector and slide the box off the bracket by prying up the locking tab with the screwdriver, move the box aside to make room to work.
Next remove the stock PCV line from below the throttle body. This is held in with quick release clips, which are a pain to get to unless you have baby hands. I set a bad example of impatience and just pried the ends with a screwdriver and removed it that way, but it is now unusable, but I don't intend to ever put it back to stock anyway. The top line is the intake manifold side, the bottom is the engine side (crankcase).
This is the line to look for, and remove.
This is where I had to do some more digging to find definitive answers, the bottom port on the engine should be connected to the bottom port on the can with 3/8" hose, and the top port on the manifold should be connected to the top port on the can with the same 3/8" hose. For this installation the Mike Norris can didn't come with enough hose, so I got 2' of 3/8" hose from work and I used about a foot and a half to go from the bottom port to the can, and used the supplied hose to do the top port.
This shows the temporary routing I used to mock things up, I later settled on routing the hoses differently to get the heater hoses to lay flat like stock.
Now is the time to put the black plastic box, its plastic line and wiring connector, and the intake breather all back in their places and route your hoses. Basically I just let the hoses and stock items dictate where to route the hoses for the can, so that they weren't in anything's way.
I also mounted the bracket with some M6 hardware in the upper most hole the factory left in the bracket next to the fuse box.
You may notice the *fabulous* blue zip-ties, I ran out of black. :nonono: But that is to keep the heater hoses clear of the bottom of the can where the drain is. Otherwise they would have rubbed on the can, because of how low I had to adjust the can in the bracket to get it to clear the hood.
And, all done! I'll update any mis-information if need be.
Discussion thread is located here: http://www.g8board.com/forums/showthread.php?t=83089