[Bus Ted Knuckle]

what carb do you have? Are you talking about the truck in your signature? Could be any number of things, I would start with checking fuel flow (filters, etc.). details would depend on the details! If it is a quadrajet and the filter(s) are clean, I would start by setting the wind-up spring tension on the secondaries to about 7/8th turn after it contacts the butterfly. If the secondaries open too soon, it'll cause it to bog.