Has anybody swapped out the factory carb with a Holley or know of a reliable replacement for a 74 opel manta 1.9? Also, will an electric fuel pump be needed?

Hi, I have a 70 GT with original Solex carb that has been functioning well but started having hesitation on initial acceleration or intermittently starving at highway speed. Decided to take carb apart and rebuild as I suspect dirt inside. So, I unbolted carb from manifold and immediately here...