What type of carb is on there now. If its a carter AVS, the tune might be in the rear secondaries. The AVS can be adjusted with the turning of a few screws. Let us know what type of carb it is. A too small cfm carb would not cause this type of problem. A carb out of tune or a distributor might be the problem. I think that edelbrock makes an excellent carb for an almost as stock replacement. Demon carbs are very tuneable, as well as Holley. If the engine is stock or mildly modded I think you might want to stay with an Edelbrock replacement. They were built just like the old Carters. Just match up the cfm. 650 cfm I think for a 383.