The lifespan of stock pistons with a buildup like you're contemplating will be measured in minutes at best. Bite the bullet and commission the best set of custom made forged racing pistons available, and follow the piston manufacturer's recommendation for clearance. They're going to rattle like there's a bunch of little guys with big sledgehammers inside the engine, trying to escape!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!