Top end questions

[Skullanova]

Hey guys first post so go easy on me please. Doing my first top end on a 09 ec250. Seems to run ok but kinda want to start from scratch with hours on the top end and it?s cold so good time to tinker. So I have Pulled the cylinder and cleaned her all up than scotchbrite on the cylinder walls but I can feel a lip up near the top. First off is it possible to get a shop to hone the cylinder with a diamond hone and will that work with the Nikasil coating that is currently on it? My second question is does anybody know the clearence tolerance between piston and cylinder if I install a Forged pistons vs a cast on or does it matter? Manual states .055mm to .1mm clearence I believe if I have her right. Or should I just slap a C piston (66.35) in it and not worry about the barely discernible ridge as the rest of the cylinder looks good with crosshatching and feels smooth?