Bugga bugga chugga bugga cruise

Hello folks, back for more help. Installed a new 1406 edlebrock on my car and was running like a dream, 67 valiant commando 273, but I've been noticing a slight miss while cruising, no idle issues, idles like a dream. At wot (when not warmed up will definitely lean out and go POP!) When warmed up no issues. Hammer down and go. But no matter warm or cold, misses while cruising. When cold a slight bogg whilst accelerating. When warm no acceleration issue. Only whilst cruising... Any advice helps