Re: wear and placement of the shims, like B1MAXX said, and based on the feedback I got from the forum on my W2 setups the 0.010" wasn't a big problem, provided that it's not short-changing you in terms of the actual load the spring is providing.
Re: seal installation tool...I had previously used the long socket but was never comfortable with the hex inside being, well hex, as opposed to circular and therefore not properly driving the seal down around it's circumference.
So here is a handy little tool that does an awesome job on this task =>
Comp Cams Valve Seal Installation ToolEDIT
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If you buy the tool make sure you get the right sized one, there are different ones given the different sizes of the seal diameters.
