Have a Defender 110 with a V8 that has twin SU carbs with a Landi Renzo LPG
conversion that was on it when I bought it. The LPG is fed in to  a  device
between the carb and the manifold. This presents a restriction to the air
flow and whilst I can see that it might be necessary to get a venturi effect
to make the system work, I am keen to do away with any restrictions to the
air flow and potential consequential power implications.

Is there a way to stay with carbs  but avoid this "restriction"?

If the restriction has to stay is it possible to fit efi in a relatively
straight forward way?

If I fit efi would it be preferable to go for the flapper or hot wire
system?

How much of the present LPG equipment would have to be replaced?

Would there be power or economy benefits from doing this work?

Gerald