Really, how can you compare a rocker cover to a bike frame which uses part of it as the oil sump. What you drinking tonight mate. Bead blasting isn't the same as sand blasting but would still need a thorough wash and blow dry before painting etc, let alone re using.ummm i dont want to state the obvious but surely the best option here is to remove it and replace the whole engine with an inline 6. there problem solved.
on a more serious note, what ever you do DO NOT remove it and sand blast it, this might sound obvious but i have seen people do this. i think the funniest was a chap brought around a bike frame he had blasted to a place i once worked to have it powder coated, this said frame came from a bike that used part of its frame as the sump, the result - you can imagine.
Tony.