I'd think could be good for performance - at least worth testing. The large diameter of that tube (really a Hanson exhaust header?) would keep friction losses to a minimun. The carb's venturi is 1/2" and the inside of a Hanson header is 3/4". The volume of the tube should allow some ram effect by allowing the air charge to compress in the tube when the port closes in front of the column of moving air, and still be moving at the carb end of the tube. The pressure would still be waiting there when the port opens again. That's how a ram manifold works. The question is how long is too long? Maybe an engineer could answer that one. Another problem that can occur is when fuel puddles inside the tube due to the air velocity being too low. That would make the carb hard to set and the engine go rich-lean-rich. Usually going lean just when you need it most, for acceleration. Puddling isn't a factor in the log-and-tube manifolds on cars since the fuel is injected downstream from the manifold.
It would also be good for a gas rigger, getting the intake under the cowl and out of the spray.
So tell us, how does it run? Looks neat.