6lb pump blowing out carb?

I just replaced the tank in my ‘75 duster. This car has not been driven much in the last 10 years and the entire inside of the tank was rusty, very rusty. It had a steel inline filter, regular cheap one you’d get at a parts store. It was so clogged with rust I could barely blow thought it, but the car ran fine. The filter was good enough to keep the rust from getting into the carb. I still plan on taking the carb apart and cleaning it out. It’s a Holley 4150 and it ran ok with 9# at idle. I will have an new eddy pump on it this weekend and hopefully it will be around 6#.