Anybody have experience with Demons. 750 double pumper’s that is.

I like the Demon's. That 750 is a good carb but to big for your setup IMO OOTB. Any carb needs to be dialed in to optimize a combo. Search speedtalk for info on tuning it.
Put a vacuum gauge on the car and video the readings at the track with your current setup. Also the paperclip on the sec vacuum rod trick will let you know if the sec open fully.
A smaller tire will help you more than a carb especially running 1/8 mile.
Demon specs:

thank you, I will use your suggestions. What size tires?