Knucklehead/ big flat front brake drum ID help

[MMasa]

I have what appears to be a -41 cast front brake drum but it has two square lugs cast into the outside face near the outside diameter. Is this an oddball for a certain year or range of years or maybe a later replacement parts counter style?
probably a simple question but knuckleheads are a bit outside of my wheelhouse.
Thanks for any help you can offer.
Mark Masa

[Jerry Wieland]

Mark

I have seen the drum as you mention but have I not really been able to id it. Lugs look like what are on a Hydra-Glide drum so I have always assumed that it is a later replacement or maybe OEM for later Servi-Car. The 1941 casting number has always thrown me for a loop as the cast drum actually started in 1940.


Jerry

[MMasa]

Thanks Jerry