In 1977 I bought a 1970 V code 4spd Dana60 4.10 Road Runner . The 6 pack had been removed and replaced with a CH4B and Carter carb . I found a 6 pack intake and bought the mechanical - non vacuum - end carbs . I think I got them from DC . Engine had 11.5:1 TRW's , .570 solid cam , 906 heads with 2.14" and 1.81" valves , Ported by a racer buddy with advice from Bob Joehnck , Harland Sharp rockers , thorley headers etc . It went to RoadRunner heaven in about 1981 or so , wish I had it back . The long and the short of it is that the mechanical carbs worked great , I had adjustable linkage to enable full 6bbl at initial throttle , or let the rod slide through the secondary carbs levers for peaceful daily driving back and forth to high school .