I installed a new Holley Carb on my 71 Javelin 360, a few weeks back, and it runs ok, but when i stomp on the gas, it surges, and doesn't accelerate smoothly. But if I press the gas abut 3/4 the way down, it pulls pretty hard.

The carb is a 4bbl 650 Holley, and the only adjustments I made to it is the idle. The timming is set at about 5* advanced. The car is completely stock other than that, and only has 35,000 miles on it.
I did replace the plugs, wires, cap/rotor, air filter, and fuel filter.

it was also doing this before i replaced the stock carb. So i thought getting a new carb would help.

Any ideas?