I have a 18 degree 428 engine in my fed 14 to1 comp ratio 950cfm gas carburetor that I had built for a dirt track car. Never used engine in dirt car, (sold dirt car with old engine) built my fed with the new engine. Made zoomie headers and ran rough would not idle right, I made collector headers and it runs great.
Would like to put zoomies on car to look original. Seems like I have vacuum problems .
What can I do to fix the problem. Thanks Don