1981 Nissan 280Z

1) Valve springs are colored blue on the end. What side faces up.
They are not symetrical--the closer coil spring spacingis on the
blue end.
2) New pistons (OEM) stick out the top of the block by 0.010"
Do I need to correct for this problem? There are 3 solutions
listed below:
a) Mill the piston tops by 0.010"
b) Install an additional head gasket (copper 0.020 thick).
b) Do nothing. Deck clearance with standard gasket will
be 0.030". This is not a race engine--can I get by with only
this amount of clearance? Do not guess--if 0.030 deck
clearance is not enough say so.
February 14, 2013.

The closer spaced side of spring (painted in your case) should be at bottom, ie engine side.

I could not find any information as to the piston to cylinder head clearance so I am not able to help you on this.

Feb 14, 2013.