"596" Head Valve/Valve Spring Questions

My suggestion is to mock up the current valves, retainers, locks and check the installed height.
Typical factory height is a nominal 1.700”, which puts a 926 spring at about 150lbs.
On top of the high seat load, that spring has a rather high rate of 415 lbs/in…….. so the open load will also be rather high.
The 926 is designed for use at a nominal 1.800” installed height.
I agree. I don't think those are his best choice.