Pistons too tall

[Ralf]

I burnt a piston in my ITB Golf due to my stupidity and therefore had to put in new pistons.


I cleaned out the bores with a hone and replaced the old pistons with a new set of Kolbenschmitts. Ran the motor and was getting what I thought was lifter noise. Replaced the lifters with a new set, and got the same result. Took off the head and thoroughly cleaned the oil passages thinking they may be clogged from piston debris. The result was still the same. Took the head off once more but this time as I was cleaning the bores out, I noticed some marks on the top edge of the pistons. That's when I realized that the lifter noise was actually the piston slightly tapping the head. Good thing I didn't go above 3500 RPM.
So the question I have is do I need to get it machined slightly or can I just shave a bit off with a belt sander? Looking at the old pistons, they were also ground down a bit. I think just removing .010 in off that edge would keep it from hitting the head.
Thanks