Stock rockers will not take that kind of abuse with those spring pressures, adding a higher lift cam over stock just adds to the problem, looks like you have some $$$$ to shell out, there is a stainless steel roller tip rocker kit with shafts/shims/bolts for 360.00 from KMJ performance (
www.kmjent.com), i would also invest in some pro-magnum lifters from comp. cams, there about 95.00 bucks through summit, just make sure your pushrods aren't gauled at the tips.