Thanks D
It's my opinion knife edging a crank is the last thing on the list of things to do on the rotational parts of an engine.
I my opinion the first thing to invest in if your building a substantial motor on the rotating parts side is a decent very light weight flywheel and clutch set up, (i've got photo's in my album) I am not a big believer of machining too much of a standard flywheel, the thought of one grenading at high revs is enough to put me off having one. (I like my legs from the shins down

) Once again it depends what your plans are for the motor, me - I race them - Hard.
Next would be balancing everything from the head down by someone who knows what they are doing, it really does make a difference.
Knife edging a crank is not a job for the faint hearted, they are very good quality steel and you really need to know what you are doing, the one in my race car at the moment took six hours non stop standing at the lathe and then there is the other jobs that need to be done, oil galleries, polishing, balancing.
Don't let me put you off, all this is only my opinion based on experience.