I brought home a pile of parts from a house clearance. !937 Master parts left over from a long gone restoration. I have a 1938 Standard. I have four brake drums. Apparently the rear are interchangeable but not the front. What is the difference?

The rear drums are flat. The front drums for a straight axle car are buldged out in the center.........

OK I'll just expand the information. Agreed the rears are flat and front bulged. The rear drums K21055 fit most cars 36-48 Standard & Master etc. Not a problem. I also have two front 38 standard drums (K21057) which fit 37 and 38 Standard and others. I also have two front 37 Master drums (K21054) which fit 36-40 Master and others.I can't see what the difference is between K21057 and K21054. Basically I am sorting out a pile of stuff which is going to someone who is restoring a 38 Standard. Thanks.

I have managed to find a spare drum off my 38 Standard (top) and put it next to the 37 Master (botton). The 37 is more like a rear drum but with a rise in the centre. The 38 has a major rise with the studs coming through a flange/disc. Quite different.

Hi Terry, I have seen the same thing as you have picked up with the drums, Front I beam hubs on 1939 models have the hub flange outside the drum, while master deluxe IFS hubs and drums are hub flanges to the inside, and drums on the outside,

Off memory the the master deluxe front drums can be used on the rear axle when removed from the hub flange, maybe Gene could confirm this,