About 48 years ago a friend and i stopped to say hi to a guy working on his 1970 Chevelle 454 drag car. He was missing a carb stud nut, thought it rolled under the car . He fired the motor, heard BANG! BANG! BANG, TINKLE, as the missing nut came out rhe collecter! Pulled the head, three dings, no other damage. The big rollercam he had in it allowed that nut to enter and exit without damage to the valves or seats!