did these parts come out of my mechanical fuel pump?

75 350 felt like it was running out of fuel at speed on the highway, found these 2 parts in the metal fuel line just before the quadrajet fuel filter. (Quadrajet fuel filter clean.) Took 'em out and the car runs fine now. Fuel pressure around 6 psi, every once in a long while bouncing wildly.

 

Looks like the check valve from a previous filter.