Believe it or not, these things would hit hard as hell. I am not sure of the exact dimensions, but it is close. Pipe was always 2" larger in diameter than sub. It was always 2' long. The port divide ran up 1'. I think the clearance was 1" and the port pcv pipe was 1 1/2". Maybe some of you have seen these actually work, maybe not. Or, maybe you have thoughts on making them/ tuning right.