add them, subtract them, multiply them, divide them, as for the numbers I would start with real numbers, then move on to prime numbers, then get into fractions. lol, I'm just fucking with you. Can't help it. I can't tell you the actual process that you need to do. I only know what you need to do. I would seriously doubt you will have problems with any piston to valve contact, however, it is always best to know for sure. I would try to contact a shop to see what their input would be. You may have to pay a little bit to get it figured out but in the long run it would be worth it IMO. Good luck.