Currently we do not know the difference between the 2.5 and 3.0 heads and whether or not either one can be put on the CNC machine using the same program. We like to start with the 2.5, since there more popular, and we will have no problem putting on 3.0 valves though I think the 5-Angle Valve job will greatly help even a 2.5 valve to make it competent or better than a single angle 3liter valve, though a 3liter valve w/5-angle will be better. Cost wise there will probably be a charge to fit the 3.iter valves to the 2.5.
