Your max rpm for your big block????

The problems with a big block oil system are the same as small block. Leaks at the lifters if they are worn because the lifters get oil before the mains and rods, and the pickup side as the biggest restriction to oil flow. Instead of spray bars, you might want to just have the cam partially or fully grooved. The upper end oiling is good already, but not constant. Spray bars are for heads that have no rocker oiling built in.