installed height versus spring pressures

well I finally got my lsm spring pressure tool. the bench one. (only had enough dough for one, so the tackle box is gonna have to wait.)

...my question is should I shim to open pressure, on the seat pressure or to the installed height spec(60679 edlebrock head)
...have a set of new springs also and there is tolerances even on the new ones. cam is a voodoo hydraulic flat tappet. thanks for any edumacation offered. will not argue with those trying to help. thanks again, bob

You're going to want to put a steel shim under the springs so that the springs are not chewing into the aluminum head. There are various thicknesses you can get. Shim it to the closed pressure that is required. If it is already too much, use a thinner shim, or you can get valve stem locks that will give you an extra .050" of height, and take a bit of pressure off the spring in the process.

thanks.....had more time to play. if I set the installed height correctly the seat spring pressure is down two pounds to 118. however the open pressure is down quite a bit. 280ish intead of 320 ish. if I bring the installed height down just a bit pressure is up to 125 but the open pressure is up to where it belongs.

….so anyway where some of the installed heights on the edelbrock heads where a little bit long side my open spring pressure would be fubarred….. hmmm