340 engine isn’t getting enough gas, why?

I’ve found very little parts for a 45+ yo car to be new. They are all refurbished and mostly poor at that. Even aircraft parts. Since there are so many variants and aftermarket, describe your fuel system tank-carb.

Electric or manual pump? Regulator? Pump cam could be flat or wrong pump, cam, cover configuration. How do the filters look? Some filters you must cut open. Any kinked hardlines? Check carb float level. Tank could be full of sealant chips, you never know.

Thats even if this is a fuel delivery problem.

Posting a video would help. AJ is right, it would be fuckin pissed off and violent.