What does the number 556789329581 mean it has been in my head for six years?
The fact that this number has been on your mind for the past six years is very likely to be a symptom of obsessive compulsive disorder. Please seek professional counseling as soon as possible, for your sake and the sake of those around you (which could be me).
THE BLOCK CASTING NUMBER IS BEHIND THE CYL. HEAD. SORRY CAN'T REMEMBER WHICH HEAD. IT USUALLY IS A RAISED SEVEN DIGIT NUMBER. THE CYL. HEAD CASTING NUMBER REQUIRES REMOVING THE VALVE COVER AND CHECKING THE RAISED CASTING NUMBER ON TOP OF THE HEAD. YOU CAN CALL A DEALER OR A ENGINE REBUILDING SHOP AND GIVE THEM THE NUMBERS. THEY SHOULD BE ABLE TO GIVE YOU THE YEARS THAT CORRESPON TO THE CASTING NUMBERS.
Why did the number of head injuries increase after helmets were introduced at the beginning of World War 1?
Field hospitals kept records of casualties. If a man arrived at the hospital with a head wound and lived, he would be listed as 'head wound', but if a man was dead, he would be listed as 'dead'. After the helmets came into service, many men were hit on the had and lived, and were listed as 'head wound', and so the number of the increase was made up of men who would have died…