bought $3 worth of A/C line insulation and stuffed all seams and wrapped all edges and it seals very tight. I trimmed the insulation from around the heat extractor vents and you can feel the intake sucking cool air through the 2 front vent holes with the hood closed. 93deg ambient out in traffic today and the IAT's never got over 110 at a full red light. Temps also creep up very slow as opposed to the rapid skyrocketing temps of the normal JLT setup.