Just to help me get less frustrated while looking at my overhead cam V motor (Nissan V6), can someone tell me why the rule that allows offset keys to be used to return cam timing to stock limits you to the crank and doesn't allow it to be done at the cam itself?

I know there are very few V-6 motors being raced in IT, but this restriction sure puts us at a disadvantage. When you re-surface the decks of a V motor, you change the cam timing between each bank differently relative to the crank. You cannot properly re-adjust the cam timing w/ an adjustment only at the crank.

W/ very few cars in this situation & the ensuing fury that would be created by suggesting a change to allow cam timing adjustments at the cam, I am only looking to find out why it was written this way.

Matt