906 head spring seat machining

I don't know how everybody else feels, but my thought on it is, slap um on and go like you are. Unless you have coil bind, piss on it, you're fine. You need to remember, after break in, your springs will lose around 10% of their pressure, so if you're a tad tighter on installed height, who gives a crap? As long as you aren't coil binding or have too much pressure on the valve train (which you will not), you are good to go. I say sling it together.