what valve seals after machining guides?

All is good, discussing things is how we learn and leave info for others down the road. After looking at the heads and what MRL said i realized that as he said i was over-thinking it. All that needs to be done is cut the inner seat down .100" and then have that much shaved off the valve guide as well and the heads will be good to .600" lift safley, which is more than likely way out of the flow range of a set of home ported magnums anyway. But its always nice to have that insurance.

Also the pushrod length shouldnt be much of an issue as i decided to go with the crane conversion and 1.6 chevy rockers to simplify things.