When discussing cylinder head machine shop work and specifically installing OS valves,, is there a need to go into details / discussions on spring seat to valve seat relationships?

using the search function I saw that installing OS valves is a good way to correct any symptoms of valve recession and if left "full" to the original height can help reduce combustion chamber volume, however it seems that would enlarge the spread between the spring seat and valve seat. Also found comments that there is not much cast material under the spring seats and machining the spring seats deeper is not recommended.

So with the machinist, should I be talking of a specific spring seat to valve seat dimension or just generally about springs and pressures. And if it is springs and pressures should I have the valve springs, retainers available,to the machine shop? I have the valves and keepers.

thanks
DT

Everything works together. Headwork, valve diameter & length, springs, retainers, even keeper-locks. Give all your parts to the shop when the work is done. After the valves are fitted to the heads, the retainers & keepers are test fit to determine the retainer-to-spring-seat distance (installed height).

Then the springs should have the recommended (closed valve)pressure at that installed height. If it's not correct the shop can ;add shims to slightly increase pressure (decrease installed height), use different retainers or keepers, (maybe cut the seats to decrease pressure / increase installed height SLIGHTLY) or choose different springs that match your particular measurements.

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63 Valiant Wagon
225 - 4 bbl