My friend had a 408 built for his 66.After he broke it in driving it 500 miles.We went to the track and on the way i was following him all the sudden his car just exploded with smoke.We got it back to his house ,pulled the intake and all the pushrods looked like wet spaghetti. On further inspection we found that the shop who built his engine had put the pistons in up side down.The damage was expensive$$$$.