Valve spring installed height?

What's the "proper" formula for minimum valve spring installed height? If my memory is correct, it's coil bind + valve lift + .075" margin and minus lash? Or have I got it wrong?

Thanks, Brian

I use from .055 to .080 from coil bind at room temps, more (.080) on aluminum heads as they get taller when warmed up making the installed height get a little shorter, moving the spring seats closer to the retainers
By the way, I check the pressures on every valve and set the installed heights based off of the coil bind clearances, not off the advertised installed heights
Sometimes I need to change the inners or dampeners around to get the pressures closer together also

I put a spring/retainer/seat on a spring tester, bring it to coil bind add .060 plus valve lift (measured not theoretical) for minimum installed height.

So can often end up different intake/exhaust and isn't always necessary to run it that tight.