MG Car Repair: SU vs Zenith carburetor, zenith carb, outright power

Question
Having owned several Volvo"s circa 1960,I have come to like the dual SU carbs.Ive read that the single zenith carb along with the intake/exh manifold used on the "76 mgb is inferior.Despite past u.s. emmision reg's for this vehicle,this is not an issue due to the cars age.Also,any other emission reg. systems that rob the motor of power which can be removed

Answer
Hi Nicholas.  I agree with you.  In standard tune, an 1800cc MGB engine with twin SU carbs produces about 100 bhp and has a wide spread of torque.  With a single Zenith and all the emissions equipment, a late USA spec engine only produces 76 bhp.  For outright power a single twin-choke Weber is slightly superior, but at the expense of flexibility and fuel economy.  So long as it is legal to fit them I would use twin SU carbs every time.