I have a flat top piston (mk4) which measures from to skirt to the bent face one and three quarter inch .

I have a cone top piston (mk2) which measures from the skirt to the bent face one and twenty three
thirty seconds of an inch .

So of the two pistons I have on the desk I am sitting at the distance of the cone top is one thirty second
shorter than the flat top piston .

The measurements were taken using a vernier caliper so reasonable accuracy .

Both these pistons are standard with no polishing .

Cheers Crowbar