I have machined a crankshaft for an AMC V8 while it was installed in the engine, but we stood the engine up on the harmonic balancer, leveled it in all directions, and used a precision boring head in a radial drill press to machine an accurate hole. That one was set up for a different torque converter since the year of the engine didn't match the vehicle it was being mated with. AMC had swapped from a Borg-Warner transmission to a Torqueflite, and the TF had a different converter snout dimension.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!