Ive noticed that piston to bore clearances are fairly up the shit with many of the US pistons atm (cant remmber the acl specs though), what are the ACL clearances on the particular model you have? I just finished a few ARIAS forged build and always go way smaller in the piston to bore clearance than recommended. Its seems many have a generic clearance.
But dont panic and keep it simple, check things like pcv, baffles in rocker cover etc..