new valve spring install

putting new valve springs on my heads that still on engine..few things need to know
[1]I read somewhere that when installing new springs you to put them in vice and collaspe them to where spring coils touches each other and release once;;said this would get the spring pressure to be correct;;what they said was when installing new spring that they drop few pounds as soon as you start eng and that would have spring pressure less then what installed them at;;by doing the vice trick that takes that pressure drop out of them..true or false?do I need to do this with new springs before installing?
[2]do I install all the springs first then take my spring pressure checker I got from LSM and check my closed spring pressure to see if where it needs to be at?if it is less then what I was told needed to be then do I just add shims till it reaches the pressure I need?

 

My take is more spring pressure is better. Period. It may be worth something on a N/A setup to run as little spring pressure as possible, but on a blown deal I like the added insurance of stable valve action. I setup my springs at .050 from coil bind. Any less than this and you get into bind problems. Any more than that the spring life is diminished due unwanted harmonics in the spring. I have used the vice trick to get an acurate measurement of coil bind on a new set of springs to make sure that the "actual" coil bind number matches the one on the box. I don't have any info on whether it helps "set" the springs or anything like that, maybe someone can chime on that. There was someone here that did a valve spring time capsule and I think that results were the spring pressure was unchanged after setting compressed for some length of time. The last thing that I have is check out a video or two of some valve springs in action on the spintron machine, you will be amazed at what is actually happening.