Use BTD's advice and go to the website. Use all the websites you have patience for. Geometry will change with newer style rockers and by addressing only the pushrod length problem, you'll create a whole new problem elsewhere, such as tip to stem goemetry or valveguide load geomtry........ This needs to be addressed before you open "Pandora's box". You didn't state the head casting number or style or what they came off of, so it's hard to give you what you need in info. There are other alternatives to achieve your goal. Give us some extra info please and see if somebody here has the solution. Keep up the good work. P.S. are you stepping up to 1.6 or just trying to get better rocker arm symetry?