here is what a swap over master cylinder will look like
https://hotrodhardware.com/products/...der-conversion
things to consider when looking for a swap over master cylinder
drum brakes have a residual valve built into the outlet where the line screws on. disc brake master cylinders don't have that feature. some rebuilt units are originally disc brake units and may not have the required residual valve. google it for a pic of actual port with res valve installed and not installed so you know what to look for
some master cylinders will have come from a vehicle that has the outlets on the wrong side so harder or impossible to get the lines connected
the reservoir fill location may not be exactly placed like the old master cyl so a larger hole may be required in the floor or a "fill from underside" method may need to be adapted
inspect the rest of the mechanical system for the pedal and ensure it is going to be serviceable. no use installing a new master cylinder on a worn out pedal system that is binding or sloppy and won't allow the pedal to function like it should
also inspect/repair the park brake system, as well as the rest of the brake system, because the park brake assists in rear brake adjustment and will help in pedal travel if adjusted correctly