I second Fred's opinion here. First, scrape the chunks then use a parts cleaner to get the rest of the grease off. With plenty of work here, you should be able to get a nice painted surface. Sandblasting to bare metal is overkill and not necessary if the components are in tact, sealed and real clean.
On the other hand, you may not see this post as I used the word "bare" while talking about cleaning a rear end! :rolleyes:
