Hello fellow x fire ers.when i reused the stock elbow it was recommended to sand down the inside two fin looking ridges.to be honest i ended up using a silicone 90 degree elbow right off the larger trottle body,as well as mounting the filters ,or filter ,on the front side of the radiator with a k&n waterproof bag like cover.I noticed the new trottle body added as much or more power than the entire cold air set up.guess thats why it is highly recommended to do both. !! !!whatever!! !! you do do ,if you have thoughts of removing the intake manifold be careful,i have heard of several problems getting them to seal correctly,for youre own sake leave the extent of upgrades no futher past the tb.bye