After seeing a Fellow Youtuber/Engine builder that also purchased a "proform" style valve spring height micrometer. I thought I would share how I calibrated mine. Hope this helps someone.
@goldsgarage8236
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https://www.youtube.com/watch?v=GfsX1eCG4VU
The Farm Truck Chevy 350 budget small block Chevy build from JUNK!! Part 11. We Put The Valve Train On And Set The Valves!!
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https://www.youtube.com/watch?v=Ga6Vhi0WynE