Years ago (over 40) I took the Carb/manifold gasket to napa and had them match a Holley Economizer Carb to it but I did have to open up the mounting hole one size because the offset was slightly different. This was on a 300 six application which should be the same. I know it was a Holley and 90% sure it was a Economizer. If that doesn't work how about auto wrecking yards. Or give Clifford a call and ask them http://www.cliffordperformance.net/h...s/contact.html