denscor

I just now got to install my yella terra rocker arms,when I installed them I got just a little more then a turn,so I used the shims with it. Now I get a little less then a 1/4 of a turn on preload.Is this OK?I called the company where I bought my heads and they told me that they where milled just 10to 15 thousands .Should I get a different shim kit because I read that there is a ford kit that is around 20-25 thousands?If so does anyone have the part number? Or should I just leave it with the 45-50 thousands shimms in it?Is this too much preload at 45-50? Also are bigger injectors noiser than stock ones?