Rich,
Pls clarify the fitting height of the following MS valve springs;
C AEA 525, C AEA 526 , C AEA 567.
as I found the attached instruction different from what the web said.
Not 100% sure of what you're after here, however the fitted height will be set by the valve, not the spring, and that height can vary depending on how many times the head has been serviced and if the spring seat has been machined.
The other things to check for is that there is enough fitted static compression in the spring to suit the cam profile and rpms you intend to rev it to and that you don't have coil bind (in fact a small coil clearance) when the valve is fully open.
Generally you'd only fit springs with enough poundage to get the job done with little extra, ie, don't over-spring it.