I am working on a 57 Chevy 3600 pick up and found the wheel bearings to be bad. This being a 3/4 ton truck the conversion to roller bearings is not available. The inner bearings and seal are readily available but could not find the outer bearing other than one on ebay for $1000. The OEM part number crosses to a B47 which is mostly a universal part number. But that number is so obsolete that I found that number also applies to a needle bearing. Doing more research I found a cross reference to a B45 with only the width of the outer race being slightly wider. This bearing is readily available and works perfectly.