underdrive pullies-to grind or replace bolt?

I was talking about care in threading the bolts. Not the relative strengths of the material. I personally have heard of more people misthreading things into iron engine blocks than aluminum engines. I am fairly sure the number of aluminum casting on an airplane are fairly small. Actually I will use a quote here. "In aircraft design, cast aluminum has been limited to noncritical components because of strength problems." Now just judging on what I see at Boeing. The aluminum they use for many parts is hardened aluminum. And there is in most cases. A considerably different standard in materials between car and areo-space industries.
 
If you are talking about the engine no there are not very many. But if bolts are such a worry. Why does Ford use bolts on the aluminum engines? I'm sure they expect people to have to work on these engines eventually.