[Oldsguy]

Well, welcome to our site, I hope you enjoy it. I would recommend that you check/replaced the fuel filter first, if that doesn't fix it perhaps a closer look at the carburetor would help. Since you plan a rebuild on the car perhaps doing the carb should be one of the items you do. A leaky baseplate gasket would allow too much air into the fuel/air mixture especially on low vacumm situations like acceleration. I am not sure about the ignition system in your car but you probably have an HEI distributor but can still adjust the timing, you might check the timing as it may be too retarded, this could cause the problem you describe (maybe). I hope this helps and let us know what turns up, ok?