The importance of measuring bell housing runout.

The story that I heard was that the manual trans cars had the bellhousing mounted to the engine, then the bell was line bored to center of the crankshaft.
I did write that in the first post.
I gotta say, I just don't buy that. Just imagine how many millions of vehicles they'd had to do that on. Stop and think about it. That would have cost them a crapton.