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Holly makes one that will go right in there............but, it can be a real job sometimes to get to it, depending on the year, make and model. I am attaching a link to one source. Hope you don't skin up your knuckles getting this out! Please get back to me if you need more on this as all follow ups are included in our fee. https://www.holley.com/products/fuel_systems/fuel_pumps_regulators_and_filters/regulators/carbureted_regulators/parts/12-803
These are adjustable and you want about 5-7 lbs pressure on this setup.