Not sure if this is the forum for this. If you live in Perth , don't go near a place called Maddington Head Factory. Mate had his 350 chev stroked there to a 383. Never seen a rougher job. Vibrated like a dog shi**** razor blades. They bored huge holes in the flywheel to try to balance it out. Wore the cam lobes off in 500km. Loud knock in the motor when cold. Takes it back to them on a weekly basis and they just let it sit there. Less power than the original 350. Lesson learnt. He has now learnt of others with similar stories of this place.