I have a D16 head I am working on and I am going to take the valves out today. Should I keep the valves+springs+retainers in separate bags and mark them for each cylinder or does that not really matter? It will be going to the machine shop to get some new seats ground and a couple other things. I will probably keep the stock springs, are they pretty decent?

 

yes always keep them in the same place some people dont and have no issues but why risk it. i like to get a box and i push the valve threw the box then the tip thats sticking up i put them back together springs retainers keepers and hang the valve just to be safe its worth it.

 

^that.
i've personally never heard of anyone having a problem switching em around but it takes ten seconds to get some cardboard and draw a pretty crappy head to put the valves in with springs, retainers and such for each cylinder.

 

usually it doesn't matter if you are having the seats and valves recut, but keeping things in order is always a good idea.

depending on the condition of the springs, usually stock spring would only be ideal for stock cams, so if you like to upgrade the cams, hen you should always upgrade the springs too.