carb manifolds vs efi manifolds are too different beast. most plastic manifolds I see are efi. I think for a carb you need heat to keep the fuel atomized.
Yes, for two reasons. Back in the day when our cars were made, they did not have the plastic technology that they have today. they could not make a plastic intake that could withstand the underhood temperature range cycles. Today's plastics are better suited for that application.
With EFI, you just place the injector by the valve and spray the fuel directly into the cylinder past the open valve.
With carburetors, the intake air has to carry the fuel vapor mixed with air from the carb to the cylinder.
Once the engine is warmed up, there is enough heat to keep the fuel vaporized.
