Stalls with electrical loads

I will try bypassing ballast for test only and see what happens. I may have to hook up the tachometer I bought for it in 1987 to see what it actually idles at in gear:) Hate that tacked on look but 73's don't have rally gauge clusters. I am going to check ballast resistance when hot too, maybe it's just a crappy part. What part numbers/brands are considered prime?

I am still going to pull the carb and check T slots too, I remember this carb gave me a bad time when I first got it used several years ago off evil bay.

Thanks again for everyone providing inputs, electrical troubleshooting has never been my specialty.