Really bogging down in 3rd gear

Could use more info. I don't even know what country your car was manufactured in. If you have a spare carb, change it out. If you still have the problem, at least you have a starting point. We are all assuming your exhaust pipe isn't crushed or plugged, air cleaner is clean, fuel pressure is good, plugs are clean and properly gapped, wires are not cross firing, cap and rotor are good, gas is fresh, brakes are released, etc. List is long.