Originally Posted By: powerpro302
How can the valve closed spring height be off by 0.21”? The damper isn’t even under compression at that height. What am I missing here?


Greetings . . . on the stovebolts the valve spring rides on a separate removable seat - not directly on the head:
Chevy Parts Master '29 - '54
specifically part 0.311. I suspect the jummies have a similar part. This will close some of the gap.

Also, I am running McGurk hold downs and a custom after market spring package. I needed to shim underneath the stock spring seats to get the right 'installed height' and corresponding seat pressure:
Inliners Post circa '14
Lucky for me Frank McGurk included the shims in the Hold Down and Inner Spring package I am using.

Substituting valves and springs you will likely have to shim to get the installed height right.

regards,
stock49