I was judging by Rick Ehrenberg of Mopar Action magazine who wrote an article on adjusting the Saginaw pump for better road feel. It is likely easier to source parts for one. I've only had TRW and Federal pumps on mine. I rebuilt the TRW in my 1965 Dart, then had to change to a Federal to get brackets which bolt to the later aluminum water pump (bad choice early on). Later I thought I could use the TRW in my 1965 Newport, but found the shaft is larger diameter and only certain pulleys have the V in the correct place. For most components, best to use what came on your car, unless you want to spend much time re-engineering and face "can't get there from here". Seems the TRW innards would be termed "radial vane" since a cylinder with slots that flat vanes slide in and out as the cylinder rotates in the oblong cavity. Some Holley fuel pumps for carbs (~15 psig) are similar.