The part number for the front lower engine stud on my 1957 Road Rocket is 27-6276. It's described as " Front engine plate, exhaust pipe and horn stud". In various parts catalogues, it's described as 8" by 3/8. At 8" long, you can just about get the exhaust brackets on, with about half a nut. There is no chance of fitting the horn bracket as well. Has anyone encountered the same problem? David.