engine misfire at half throttle

[sean68charger]

my 440 pulls well low down, starts to misfire at half throttle as if when the vacuum secondaries are just opening, but obviously cant tell as it only happens when the car is driving, then as i give it full throttle it clears and pulls like a train, is this an ignition problem or carb problem?, if it was ignition surely it would missfire all the way through the rev range?
it is fitted with electronic ignition, new leads and cap, new coil etc. it also has a holley 750 vac sec

[firefighter3931]

Sounds like a fuel delivery issue to me. Check the float level on the secondary bowl. 



Ron