I recall this problem you were having with this from another thread,you allready had the crankand rods balanced before getting them ground for clearance. So as you say this does restrict you in your cam selection. As for amplifying through rocker arm ratio up to 1.65 you can get away with it on the stock geometry. But 1.7 and higher you either need to move the rocker arm stud or maybe go For the expensive shaft mounted rocker system, and even then you are going to have excessive valve gyide wear. Maybe the other option is to go for a roller cam combo with long duration and mild lift, but that will probably make the power band peaky. So these issues alone with the expense involved Could Force you to grind and rebalance the rods and to put it down to experience.