How does the intake side get too tight? Sims like as the shim smushes it would get looser? Maybe I am thinking about it backwards.

I will measure with filler and then used a caliper to find the shim that get me close to the measurement I need. I have a shim kit. Any concerns getting the timing off doing this? Or as long as I line the cam marks on the sprockets back where they were I will be good?