This shape is taken from the world famous Harley XR 750 flat tracker. The intake port floor is raised for increased velocity and flow, allowing for a fuller intake charge. Made of alum. An easy drop in kit but some raised porting at 10:00 and 2:00 near the guide may be required for increased performance (see instructions).  Add a dab of JB weld to hold it securely - align with valve guide and tilt into place.  Two reusable teflon heat insulating gaskets included (more images) (installation instructions).

This shape is taken from the world famous Harley XR 750 flat tracker. The exhaust port floor is raised for increased velocity and flow in exacuating spent gasses and allowing for a fuller intake charge.  Conical shape is already there for the exhaust pipe.  Made of steel. An easy drop in kit - simply align with valve guide and slide into place (more info).