A head rebuilder assembled my 20v head partially and left me with camshaft and timing chain installation. Some valve lifters seem different: Some rotate freely and are spongy (you can push them downward and they feel soft), others are firm on top of the valve stem, but rotate freely and smoothly, others are very tight almost to the point of feeling like they are binding. Is this normal? I plan to put the cams on and make sure that none of the lifters are sticking and holding the valves open. If not, I will proceed.