Piston and cylinder assembly, Tips? Options

[TheCabinetmaker]

Doing a top end on a 1.7L. New c/p's. New heads.
The p/c assemblies seem to be quite dirty. Should I take them apart and clean and relube evetything? what should I clean them with. I read about weighing the pistons. Should I check the ring gap, or assume(I hate that word) the were checked when assembled.

This ain't my first time, but it has been a "few" years.

Thanks, Curt

[914ghost]

Why would new p/c's be dirty I wonder?
If they're out of the box try some light solvent- like white gas ro alchohol. Maybe it just cosmoline, it protects the surface.
And DONT grind the skirt, that helps make the piston run straight- I dunno, pistons are different depending on who made them, you usually have to grind inside somewhere there is most material.
Also, weigh the wrist pins, if one is heavy you could stick it in a light piston (if the fit is right) to get them closer.
I don't know what everyone uses for tolerances on them, they aren't "rotating" parts so not as vital as rods / flywheel. I balance rods using a letter scale to like 0.10 grams give or take, then dynamically balance w/crank. Pistons...? Maybe1-3 grams (if at all) would make me pretty happy. Depends on how much I care about the engine.
Just my take again, you'll hear better advice.
Robert O