1966 Commando 4 bbl Carb.

I am using the 1403 Eddy (electric choke/ 500 cfm) but the intake is Offenhauser so there is no secondary valve restriction. The 1404 ( manual choke/ 500 CFM) would have the same problem with the secondary size. I hear a small amount of machining can open those up and work fine... but of course not a quick bolt on job without the spacer.