Hey Bill, you'd be the one to ask about this, daughter's 9" is out of a 63 ford car, can't remeber the name, but on ebay I always see detroits for 9" going fairly cheap, but they will always say " Detroit locker for Ford 9", H case" or G case or N case. What is the difference in all these cases and how do you tell what you have? And these ones that say "one race use" are they any good? Greg