Okay, I see your point on the heads. If everything you have on the shelf needs some work then it is a "pick your poison" sort of a thing. Buying a head from Summit and using it to check fitment seems like a good idea. You can return it after a few days of fit checking if it doesn't work out. I was assuming that you had some good heads sitting on the shelf and I knew that you already had the shortblock pretty much together.