Valve Spring Specs? Anyone?

My brother is rebuilding the head on my '84 Euro 635, M30-B34 and wants to know the spec requirements for the valve springs AFTER installation so he can shim if necessary.
Oddly the info is not in my Bentley manual, everything about the head but spring info.

Part number for the spring is 11-34-1-276-504
He is mainly interested in the following:

- Installed height
- Spring pressure with valve closed
- Spring pressure with valve open
- Coil bind dimension

He is interested in hard numbers which I suspect are probably only found in a BMW shop manual/data base.

Thanks for any info

The question is moot at this point.
I've checked all of the available manuals online and they have nothing on valve springs.

The valves are installed.
All new springs were measured with some very slight variations in height found.
Valve stem heights measured and the springs installed accordingly to match.
-( All new intake valves and the exhaust valves reground).
Spring pressures were tested at open and closed positions and my brother decided that he wanted to bring the pressures up a little so he shimmed all the springs .030".
He estimates that the machine work on the seats and valves took up to .015" from new specs so the net gain on the shims is closer to .015".

So, the final numbers for spring pressures are 56 to 58 lbs closed and close to 122 lbs open. (in case somebody wants to check theirs before disassembly to get a baseline).

did you check in the workshop manual? The top one, nominal values https://www.bmwtechinfo.com/repair/main/