hello people after some info and opinions i have an f plate saph owned for a few years now and like to think it was close to the 500 brake bracket i have taken it off the road to rebuild the engine as it had a knock and piston slap which i spoke about yesterday today i am trying to decide wat to do with the head as i have a choice of 2. 1 of them has 25 mm inlet ports and 24mm exhaust with a bd14 and a bd10 the other has 27mm inlet and 26mm exhaust with equivilent to bd16s which head would be best to use and why?