There are two,........... possibly three pl;aces where material is separated from the fuel.
1. Strainer at the fuel pickup in the fuel tank. If one is used in Datsuns [& I don't know if one is] then it prevents small rocks from entering the fuel line.
2. Inline fuel filter in the engine bay. This is the main filtering location. Replace it at any time that you think it could be causing a problem.
3. Gauze strainer under the needle & seat. This is the last line of defence & you need to remove the top of the carb, then the float & needle & seat assembly in order to access it.

Ddgonzal is right, the engine doesn't care what the pump looks like, as long as the mounting flange is the right shape & the arm is the right length, then it'll be good to go.