Easy killer. I still have 4 or 5 4 barrels and a 2 barrel laying around the shop. next to a 8v-92 blower....
Just trying to seel a little modern modification (megasquirt fo lyfe, yo)
Back to topic, if the carb is a holley squarebore, the kit to put a choke on it is usually like 30 extra, so it is often omited during an install. The squarebores tended to have either an electric choke or the heater element that went into the exhaust crosover (intake heater) so it would disengage as the engine heated up. If some of these components are rusted (or missing) this would make for hard starting. If you have a spreadbore and want to put a manual choke on it, the manual choke for a holley squarebore will fit, with a few minor mods. If you still have a quadrajunk on it, good luck ever getting it tuned right. carter AFBs and edelbrocks are unkown to me, never delved into them.