occasionally run into rough idle with my engine. car has been on road about a week and i have ran into the problem several times. it is a holley street avenger on top of a 355 SBC. revving it up to about 5500 usually clears it out but not today. motor has about 250 miles on it still breaking it in. any suggestions?

 

Anyone?

 

would swithching to a 750 dp help with these issues and also with my performance

 

A double pumper might help performance, depending upon what all you've got in, on, and behind the engine.

Changing the carb might help the problem if the problem is the carb. But not because you put a DP on it.

Is there any pattern to the times it exhibits the roughness? As in, when cold, when warm, when hot, after cruising, etc.

How are you reving the engine to 5500 RPMs, in neutral or under load?

Could as easily be an ignition problem as a carb problem. More likely, even.

 

it can be all over sometimes when the motor is cold and others after cruising. the idle mixture might be a little to lean.