It seems to be a popular brake conversion, right? And, people put them on over top of '40 Ford brakes, right? On other cars (non '40 fords, and any other Ford w/ 12" brakes), why not use the Buick backing plates? (That was the question that's been bothering me.) It seems like a lot of machining is required to run them on the Ford backing plates, wouldn't it be a lot easier to just install the Buick parts that work with that drum? Please help me out... I'm getting tired of not sleeping at night.