Did the factory measure runout on every bellhousing that left the factory? Of course not. I guess what I'm saying is, there has to be a pretty wide tolerance there, or else we'd have seen lots of damaged parts from the factory.
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.
