My uncle and I are working on rebuilding the 454 motor out of his 99 GMC 1-ton dually. We are stuck because we can't figure out how to time the timing chain. We replaced the chain, and 2 sprockets. Now, we don't know where the dots line up to time it right. We have heard and seen 12 oclock and 12 oclock, 12 oclock and 6 oclock. We very much want to get it right on the first go. Anyone know where the dots should line up at? Thanks.