1939 thru 1948 Ford rear wheel cylinders use the same 1 1/18 to 1 inch step down as KF, however, the hose inlet size differs so an adapter would be needed to make them fit. You're better off with the set from KF Parts, they're the correct parts. If you're looking for just the front cylinders, go to kfparts.com - he sells them individually as well.
