My GTX isn't running right!!!!

I have a 1967 GTX and I can't get it to run right. It has alot of hesatation when I get on it, its like I have no power in the pedal. I think its the Carberator but i'm not sure. It has a 440 Magnum that has been bored .020 over with oversized pistons and milled heads. I running the stock Carter 4 barrell Carb(600cfm), I'm think I need to go with a bigger carb like and Edelbrock or a Holley 750 or 800 cfm. So tell what you guys think.

Has your car been parked all winter? Likely one of the circuits in the carburetor has become clogged due to gum deposits from evaporated fuel, or just dirt. My guess is either the accelerator pump or the main jets.
A carb cleanout and rebuild would fix it up.
As for a larger carb, if your engine is stock, the carb you have is good. A larger carb likely will not give you much more power on its own, unless it is combined with other modifications, like headers, camshaft, etc.

The motor (440ci) has been bored .020 over and the heads have been milled and it has a new cam but I don't know the cam lift. And I know carburators work with the size of the engine. So a 600 cfm carb would choking my motor down right now. So rejected my Carb now might make it run a little better but I'll still be starving the motor of gas and it won't make as much power as it should.

Hey Bad,
I've tried several carbs on my 440, from a 600 to an 850 dbl pumper, all Holleys. It is mainly stock. I run a 780 vacuum secondary Holley, jetted 76 in front,78 in back. This gets some mileage without being too lean. A 600 is too small in my opinion.

Ditto to what MagicRat said.