Read the parts books carefully before choosing a V-12 pump! I took a look last night, as the only V-12 pump I have personally looked into did not look like much. There were about 4 pumps for the H motors from '36-1948... Dig through the parts chart and you will see that the earlier ones used the same gears that flatheads used in their first several year, actually the same size gears used in Model A. I did not take the time to digest the tangle of parts info, but I think only the 1946 up ones are going to differ from early V8, which could only be described as adequate.
edit:
(56H part number, meaning postwar V12, is presumably the one thought of as high capacity. Earlier ones are Ford based, only the 56H contains gears with Lincoln rather than Ford numbers)