I recently did a rebuild on my 360 and the machine shop bored the cylinders too large. The forged piston manufacturer recommended a clearance of .005 and we ended up with .008. Slap city, even when the engine is fully warmed up. Sounds like my Cummins at a stop light. My machinist suggested knurling the pistons to take up the extra clearance, .003. Anyone have any experience with this?