Gasket scraper will be OK.
I like the 4'' wire brush with the 1/4'' shank. This can run in any drill although a high speed drill works the best.
A cheap tap and die set will work for chasing the threads, but be careful!!!
I just don't trust some cheap tools.
Try oven cleaner on the baked on oil on the underside of the intake.
If you want to use a wire brush in conjuntion with a cleaner such as Castrol Super Clean, make sure its one of those with a handle so you don't give yourself a shower.