Not too much I'd think. but you change the crankcase volume when going to the big bore kit with the grinding so you might be trying to force too much volume in to the smaller bore. This is a great question for Eric Gorr. It might fit well in his forum...I don't think he treads over here too often.
BTW in most stock class rules if you have modified the case then even with the stock top end you could still get nailed. Depends on how they treat the teardown. If the just pop the top and measure bore stroke or do they take off the entire cylinder. If so they might notice the modifications. I'd probably only be worried about something like that at the Loretta qualifiers.