For general principles, might check the torque on the carb base nuts. If you used the supplied "thin" gasket, I had something similar, but not quite as intense, when I put the Holley 2210 in place of the Stromberg WWC on the '66 Newport 383. It'd be fine for a few weeks, then the idle would get a bit less smooth. About 1/16 turn on the carb base nuts would fix it. After I put the thick OEM base gasket on it, no more issues. BTAIM. The type of gasket really shouldn't matter, but it seemed to.
Just some thoughts,
CBODY67
Just some thoughts,
CBODY67
