The HPS Performance Parts intake hose kit was designed in-house and is intended to be a direct fit. Notice the hoses are not symmetrical. The OE design uses a slightly shorter hose after the bend on the driver side hose.
Removal of the OE intake elbows is not very difficult either. Worm screw style clamps hold both ends of the OE intake elbows. When removing the intake elbows be sure to remove the MAF/Intake-temp sensor wiring that runs on the bottom of the OE elbows.
When you remove the elbow you'll probably have a bunch of gunk surrounding the entrance to the plenum. Clean all of it off and make sure it does not get inside the plenum.
These rubber seal rings must also be removed before you can install the HPS silicone hoses. Ours probably have not been moved since the car came off the assembly line so we needed to use a little persuasion to take them off.
The OE intake elbow is hard plastic and is corrugated in some areas. For the most part the diameter of the OE intake elbow is 70mm, but in some areas the OE intake elbow necks down to 65mm.