Shaggy my suggestion would be to select a Hilborn mechanical fuel pump to match the Hilborn 2-port injection youre seeking for your early 1960s theme build. Per the Hilborn Injection website, a PG150 series, size #1 Hilborn pump will work with your engine combination and would be the minimum size Hilborn fuel pump to acquire.
Another suggestion for you when you are ready to purchase a fuel pump is to call Spud at FIE. Spud has new, and he may also have a used Hilborn pump that he has checked out and has it ready to go. That will save you one important step when readying to fire your engine the first time. You will have peace-of-mind knowing you have a good mechanical fuel pump which will not cause any engine running headaches.
Following is an excerpt from the Hilborn Injection website and the link to their website. Hope this is okay with Spud and Glenn, if not please delete. Alan
http://hilborninjection.com/mechanical-tech-support/The first digit of the serial number stamped (not cast) into HILBORN pump castings indicates the pump volume. The following list is a guide to help you select the correct pump size for your fuel requirements:
PG150 series
size #00 Extremely small engines such as motocycles.
size #0 Medium size engines, 200″ to 360″, running gas or methanol. Use with carburetors or small turbo engines.
size #S0 (Super-0) Medium size engines, 360″ to 410″, running gas, methanol, or small amounts of nitro.
size #1/2- Same as #S0, just a higher pump volume.
size #1 Large engines on gas and small amounts of nitro. Also for blown engines on gas, methanol, and small amounts of nitro.
PG175 series
size #2 Large engines with high percentages of nitro and blown engines on methanol.
size #4 Very large engines, high percentages of nitro, and blown engines on nitro.
PG250 series
size #5 Largest pump volume. Very large engines on nitro. Also for turbo or supercharged engines.