(oversized factory pistons, oe rods, pins, bearings) and 600s. 2000k miles on the engine and no problems so far. currently running 15 psi on the street. took it to the drags last friday and my best time was 12.8, and best trap speed was 112, but i absolutely sucked at driving. it was my first time ever, so theres only room for improvement. i was running about 19 psi on 94 octane with no detonation. From everything ive seen the stock internals are very strong and should be able to handle 500s or 600s no problem