Sputter

I also posted this on my member resto thread. But I am having an issue with my 74 scamp 318 2bbl automatic . It starts up easy and runs great until step on it even a little and it gets sputtery. I have gone through the carb. done all of the tune up & timing basics. I bypassed the OSAC valve and ran nuw vacuum line from the dist. checked the fuel filter, pump and lines. the car starts and runs great but once you give her throttle she toastfalls on her face.

I am thinking the vacuum advance on the dist has failed. Anyone have any other ideas?