I didn't have the patience to read through the whole thread, so maybe someone said this. But the max lift for a given spring is NOT just a function of the spring. It also depends on the installed height and a number of other factors. If a spring is installed at 1.800" and binds at 1.200", if you leave 0.050" for clearance the max lift will be 0.550". But if you install the same spring at 1.850" you could use them up to 0.600" lift. However, just because the spring can handle the lift, there are other clearances that have to be checked. The most common problem area is the retainer interferring with the valve seal. This may occur before coil bind. Don't ask me how I learned this, suffice it to say it was the "hard way". There are other possible interferences. Don't just trust your calculations.

Of course, the spring has to be selected to give an acceptable seat pressure at the desired installed height as well as a spring rate that provides enough open pressure.

Rich Krause