I'm repurposing an old stock car motor and need to replace the roller rockers with stamped roller tip rockers. The regular ones with the grooved ball trunion. I know getting plenty of oil on these is critical to prolonging their life and the valve springs benefit from oil too. So, do I remove the oil restrictors in the back of the block? I've also heard that drilling them out is the best of both worlds. If so, what drill size would I use.
